REPORTS 


GEN.  JOHN  NEWTON,  U.S.A., 

GEN.  Q.  A.  GILLMORE,  U.  S.  A., 

WM.  E.  WORTHEN,  Esq.,  C.  E., 


TO  THE 


COMMISSIONERS  OF  DOCKS, 


THE  BULKHEAD  WALLS 


CANAL  AND  KING  STS. 

North  River. 


1876. 


Ex  ICtbrta 


SEYMOUR  DURST 


When  you  leave,  please  leave  this  book 

Because  it  has  been  said 
"Ever  thing  comes  t'  him  who  waits 

Except  a  loaned  book." 


Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


REPORTS 

OF 


GEN.  JOHN  NEWTON,  U.  S.  A, 

GEN.  Q.  A.  GILLMORE,  U.  S.  A., 

WM.  E.  WORTHEN,  Esq,  C.  E, 


COMMISSIONERS  OF  DOCKS, 


THE  BULKHEAD  WALLS 


CANAL  AND  KING  STS., 

North  River. 


1876. 


ERRATA. 


Page  ii.  Eleventh  line  from  top,  for  "  structure"  read  "structures." 

17.  Second      "      "     "     "  "  leveling,  of "  read  "  leveling-off." 

17.  Sixth         "      11      "  "being"  "    11  was." 

23.  Seventeenth  line  from  top  ;  omit  the  word  u  each." 

33.  Thirty-third    "      "      "     for  "  field  "  read  "  seam. " 

44.  Twenty-third  "      "      "     after  "on  the  other"  insert  "hand." 

44.  Twenty-eighth  line  from  top,  for  "  met  "  read  "  me  ;"  and  for  "  me  "  read 

45.  Tenth  line  from  top,  for  "  Plate  "  read  "  Plate  I." 

46.  Tenth   "      "      "     "   "  ounding"  read  " sounding." 
46.  Twenty-eighth  line  from  top  ;  omit  the  words  "  see  sketch." 
48.  Fourth  line  from  bottom,  for  "  horizontal  "  read  "  horizontally." 
53.  Ninth  line  from  top  ;  omit  the  words  u  see  sketch." 
53.  Twelfth"     "     "       "      u      "     "  see  shaded  part  of  sketch." 

53.  Third  line  from  bottom  ;  omit  the  words,  "  see  shaded  area  at  X." 

54.  Second"      u        "        for  "  Plate  "  read  "  Plate  II." 
59.  Twenty-second  line  from  top,  for  "  enter  "  read  "  enters." 


Digitized  by  the  Internet  Archive 
in  2013 


http://archive.org/details/reportsofgenjohnOOnewy 


DEPARTMENT  OF  DOCKS. 


COMMUNICATION  TO  THE  MAYOR. 

Department  of  Docks,  } 
New  York,  September  22,  1875.  f 

Hon.  W.  H.  Wickham,  Mayor  : 

Sir — The  undersigned,  Commissioners  of  the  Department  of  Docks, 
have  the  honor  to  transmit  herewith  report  of  the  Engineer-in-Chief  of 
the  Department,  in  which  is  detailed  the  result  of  examinations  made 
of  sections  of  the  sea-wall  now  nearly  completed  at  Canal  Street 
and  King  Street,  North  River.  We  invite  your  careful  attention  to  this 
report,  and  to  the  following  brief  narrative. 

The  original  plan  for  the  construction  of  the  sea-wall,  devised  by 
General  McClellan,  the  then  Engineer-in-Chief,  is  known  as  the  beton 
block  system,  which  consists  of  the  formation  of  massive  concrete 
blocks  formed  in  molds,  and  manufactured  in  the  open  air,  in  such 
sizes  as  the  nature  of  the  work  demanded.  These  blocks,  when  prop- 
erly hardened,  were  lowered  by  the  aid  of  the  large  floating  derrick  to 
a  foundation  of  piles  firmly  driven,  and  then  sawed  off  so  as  to  form  an 
even  bed.  An  example  of  this  system  of  construction  is  found  at  the 
Christopher  Street  section. 

In  the  month  of  July,  1873,  General  Charles  K.  Graham  was  ap- 
pointed Engineer-in-Chief  of  the  Department,  in  place  of  General 
McClellan,  who  had  resigned. 

It  appears  from  the  records  of  the  Department,  that  in  the  month  of 
October,  1S74,  with  a  view  to  more  economy  in  the  construction  of  the 
sea-wall,  the  Engineer-in-Chief  recommended  to  the  Board,  as  a  sub- 
stitute for  beton  blocks,  that  concrete  en  masse  should  be  formed  upon  a 
foundation  of  piles  in  a  wet  caisson,  the  concrete  being  lowered  to  its 
place  within  the  caisson  (by  appropriate  machinery),  in  tilting  buckets, 
and  then  left  to  harden  in  a  solid  mass.  The  heads  of  the  piles  were 
not  cut  off  after  being  driven. 

In  the  month  of  November  following,  our  predecessors,  by  formal 


4 


resolution,  adopted  the  recommendation  of  General  Graham,  and  or- 
dered the  work  to  proceed,  which  was  done,  and  about  347  feet  were 
constructed. 

For  particulars  concerning  this  system  of  bulkhead  wall  construc- 
tion, see  report  of  General  Graham  herewith  enclosed. 

The  new  Board  of  Commissioners  was  organized  on  the  2d  day  of 
May  last,  and,  on  the  2d  of  June  following,  General  Graham  resigned 
the  office  of  Engineer-in-Chief,  and,  as  soon  as  practicable,  his  succes- 
sor, George  S.  Greene,  Jr.,  was  appointed  to  fill  the  vacancy. 

The  attention  of  Commissioners  being  called  to  possible  defects  in 
this  method  of  construction,  the  subject  was  referred  for  investigation 
to  the  Executive  Committee,  who  directed  the  Engineer-in-Chief  to 
make  a  careful  examination  of  the  work,  and  report  the  result. 

The  difficulties  attending  the  examination  in  turbid  water,  and  the 
results  thereof,  are  explained  in  the  Engineer-in-Chief's  report.  The 
examination  has  proceeded  far  enough  to  excite  in  our  minds  very 
grave  apprehension  as  to  the  safety  of  that  portion  of  the  wall  covered 
by  the  report. 

If  our  apprehension  should  be  well  founded,  we  desire  to  avail  our- 
selves of  such  remedy  as  the  combined  wisdom  of  the  highest  authori- 
ties may  be  able  to  suggest.  This  is  not  only  due  to  the  great  interests 
of  the  city,  but  it  seems  also  just  that  individuals  who  may  be  consid- 
ered responsible  for  the  work,  should  have  the  advantage  of  the  fullest 
and  fairest  examination  of  it,  by  a  body  of  men  of  such  capacity  and 
character  that  their  decision  shall  be  accepted  by  all.  We  have,  there- 
fore, thought  it  desirable  to  have  an  examination  of  the  wall  covered  by 
this  report  made  by  three  engineers  of  the  first  eminence,  and  to  invite 
their  suggestions  as  to  the  remedy  to  be  applied,  if  any  is  thought 
necessary  by  them. 

That  we  may  secure  the  utmost  impartiality  in  this  investigation,  we 
have  deemed  it  proper  to  request  your  Honor,  as  the  Chief  Magistrate 
of  the  city,  to  name  three  suitable  persons  for  this  purpose. 

Very  respectfully, 

S.  H.  WALES, 

H.  F.  DIMOCK, 

JACOB  A.  WESTERVELT, 

Commissioners  of  Docks. 


REPORT  OF  THE  ENGINEER-IN-CHIEF. 

Department  of  Docks,  j 
Office  of  Engineer-in-Chief,  > 
New  York,  Sept,  1 6, 1875.  ) 

To  Hon.  Henry  F.  Dimock,  Chairman  Executive  Committee  : 

Sir : — Immediately  after  my  appointment  to  the  position  I  now  hold 
in  this  Department,  I  received  a  communication  from  the  Executive 
Committee,  calling  my  attention  to  certain  reports  received  by  said 
Committee  in  relation  to  the  Canal  Street  section  of  the  bulkhead-wall, 
and  requesting  "  that  you  will  make  a  most  thorough  investigation  and 
examination  as  to  the* character  of  the  work  performed,  and  the  man- 
ner of  constructing  the  section  of  wall  referred  to,  and  report  to  them 
in  writing  the  result,  and  your  opinion  in  regard  to  the  construction  of 
said  wall." 

In  accordance  with  the  above  I  have  made  constant  examination  ot 
the  Canal  Street  section,  and  have  also  examined  the  King  Street  sec- 
tion, which  was  built  upon  the  same  plan  and  principle,  and  have  de- 
voted as  much  time  as  possible  to  this  subject,  consistent  with  my  other 
duties.  The  examination  of  these  walls  has  taken  much  time,  because 
the  greater  part  of  them  lies  under  water,  and  had  to  be  examined  by 
means  of  divers  in  armor  ;  and  although  I  have  not  yet  been  able  to 
make  so  complete  an  examination  as  I  wish  to,  I  have  ascertained  cer- 
tain facts  in  regard  to  them,  which  I  deem  it  my  duty  to  lay  before  you 
at  the  earliest  possible  moment. 

The  Cinal  Street  section  embraces  90  feet  of  wall,  completed  before 
my  appointment,  and  in  front  of  which  New  Pier  No.  34  was  also  built 
before  my  arrival  on  the  field,  and  about  90  feet  more  in  progress  ot 
construction  at  that  time.  Upon  examining  the  method  of  the  work  I 
found  it  necessary  to  at  once  make  several  changes  in  the  details,  and 
although  feeling  a  lack  of  confidence  in  the  principle  of  construction,  I 
decided  to  allow  this  portion  of  the  wall  under  construction  to  be 
finished,  taking  care  that  the  method  of  doing  the  work  and  the  details 
should  be  such  as  to  secure  a  good  result  if  the  principle  admitted  it. 

The  general  plan  of  construction  was  as  follows :  The  mud  was 
dredged  out  on  the  site  of  the  wall  to  about  twenty  feet  below  mean 
low  water.  Round  piles  were  then  driven  for  the  wall  to  rest  upon,  by 
means  of  a  follower,  to  such  depth  that  their  heads,  or  tops,  were  about 
fourteen  feet  below  mean  low  water.    A  box  or  wet  caisson  was  then 


6 


constructed  around  the  round  piles,  to  give  shape  to  the  concrete  and 
prevent  the  cement  from  being  washed  away  before  it  had  time  to  set. 
This  caisson  was  built  by  driving  square  piles  about  eight  feet  apart 
and  placing  shutters^or  panels  of  plank  between  them.  It  was  not  in- 
tended to  shut  out  the  water,  but  to  prevent  currents  from  washing  the 
concrete,  and  to  give  the  concrete  shape  and  hold  it  in  position  until  it 
had  become  hardened  or  "  set." 

The  spaces  between  the  round  piles  were  than  filled  in  with  small 
stone,  to  about  sixteen  feet  below  mean  low  water,  the  outside  of  the 
caisson  being  embanked  at  the  same  time  and  to  the  same  height  with 
rip-rap  stone. 

The  interior  of  the  caisson  was  then  filled  with  concrete,  lowered 
through  the  water  in  a  box,  and  deposited  by  opening  the  box  near  the 
bottom,  and  allowing  the  concrete  to  fall  out  upon  the  small  stone 
lying  between  the  piles,  and  upon  and  around  the  piles,  to  the  height 
of  about  twelve  feet,  or  two  feet  two  inches  below  mean  low  water. 

At  this  point  the  top  of  the  concrete  was  levelled  to  receive  the  first 
or  bottom  course  of  the  granite  facing,  which  was  then  laid,  course  by 
course,  to  the  top  of  the  wall,  the  concrete  backing  being  also  raised  to 
correspond  with  the  courses  of  granite  as  each  was  laid. 

Having  taken  care  by  instructions  as  to  details,  and  by  sending  Diver 
McDonald  down  under  water  to  place  every  box  of  concrete  in  its  pro- 
per position  as  it  was  lowered  under  the  water,  I  examined  the  wall 
already  built  under  New  Pier  No.  34.  Passing  under  the  pier  in  a 
boat,  I  found  that  all  the  square  piles  of  the  caisson  had  been  removed, 
but  only  three  of  the  shutters  or  panels,  or  about  twenty-three  feet  out  of 
ninety.  All  the  other  shutters  were  jammed  against  the  face  ot  the 
wall  by  a  mass  of  rip-rap  stone,  piled  against  them  to  an  average 
height  of  about  seven  feet  below  mean  low  water.  They  never  have 
been  removed,  and  the  face  of  the  wall  has  never  been  properly  exam- 
ined, nor  can  it  be  until  the  stone  and  panels  are  removed. 

The  stone  lying  against  them  are  too  large  to  be  moved  by  the  divers 
(they  estimate  some  of  them  to  weigh  nearly  a  ton),  and  some  device 
with  steam  power  must  be  used  to  remove  them. 

Upon  questioning  Diver  McDonald  as  to  the  examinations  made  by 
divers  of  the  face  of  the  wall,  he  informed  me  that  he  had  made  all  the 
examinations  under  water  up  to  date,  and  they  consisted  of  an  examin- 
ation of  only  one  panel  (about  eight  feet)  out  of  ninety  feet  of  wall  built 
and  lying  under  the  pier ;  that  on  this  one  panel  he  had  found  the  face 
of  the  concrete  wall  good,  smooth,  and  hard,  for  about  six  feet  down 
from  the  bottom  of  the  granite,  but  below  that  the  concrete  had  fallen 
away  from  the  mass,  and  the  face  curved  in,  and  back  from  where  it 
should  be,  till  it  reached  the  piles,  when  it  just  covered  the  second  row 
of  piles  from  the  front  (a  distance,  of  over  two  feet),  and  leaving  the 


7 


front  row  of  piles  bare  of  concrete  and  useless,  not  supporting  the  wall 
in  any  way.  By  the  falling  off  of  this  outer  bottom  face  of  the  wall,  its 
tendency  to  rotation,  or  rolling  over,  is  vastly  increased,  and  especially 
so  when  the  earth  filling  or  embankment  is  placed  behind  it.  In  this 
particular  case,  however,  the  pier  being  built  against  the  face  of  the  wall 
will  probably  prevent  any  such  disaster. 

I  directed  Diver  McDonald  to  go  down  and  carefully  examine  as 
much  of  the  face  ot  the  wall  as  he  possibly  could.  He  did  so  and  re- 
ported to  me  that  the  three  panels  near  the  southerly  side  of  the  pier 
were  all  that  he  could  get  at ;  one  of  them  he  had  examined  before, 
and  they  were  all,  extending  over  a  distance  of  22  or  23  feet,  in  the 
same  condition  of  the  one  previously  examined  and  above  described. 

This  is  all  that  has  been  examined  of  that  part  of  the  wall  under 
New  Pier  No.  34.  The  removal  of  the  rip-rap  stone  in  front  of  the  re- 
mainder  of  the  wall  will  be  a  work  of  some  time.  Its  condition  may 
be  better  than  that  part  examined,  or  may  be  worse. 

That  part  of  the  wall  directly  north  of  New  Pier  No.  34,  being  under 
construction,  was  completed  to  the  level  of  the  base  of  the  coping.  On 
the  25th  August,  a  crack  was  discovered  just  north  of  New  Pier  No. 
34,  and  upon  applying  the  instruments,  it  was  found  that  the  wall  had 
settled  about  ^  of  an  inch  at  a  point  78  feet  from  north  side  of  the  pier, 
and  prortionately  between  said  point  and  the  crack,  and  that  it  had 
moved  out,  or  westwardly,  at  the  same  point  about  the  same  dis- 
tance. 

Two  shutters  or  panels  were  taken  up  on  the  face  of  the  wall,  about 
60  feet  north  of  the  pier,  and  the  Diver  McDonald  sent  down  to  exam- 
ine. He  reported  the  face  of  the  wall  good,  smooth,  and  hard,  for  10 
feet  8  inches  down  from  base  of  granite  ;  from  that  point  down,  the 
small  rip-rap  stone,  intended  to  be  placed  between  the  piles,  and  not 
higher  than  two  feet  below  their  tops,  lay  under  the  concrete,  and  ex- 
tended down  to  the  tops  of  the  piles,  and  below  the  tops  of  the  piles 
between  them.  These  stones  were  wedged  between  the  overlying  mass 
of  concrete  and  the  top  of  the  piles,  so  that  at  this  point  the  weight  of 
the  wall  rests  upon  a  pile  of  broken  stones,  lying  on  top  of  and  around 
the  piles.  This  condition  of  things  is  not  due  to  the  principle  of  con- 
struction, but  is  directly  contrary  to  it,  and  is  the  result  of  carelessness 
in  doing  the  work.  A  diver  should  have  been  sent  down  to  remove  the 
stone,  and  see  that  they  were  in  proper  position  before  the  concrete  was 
deposited.    No  more  panels  have  been  taken  up  as  yet  at  this  point. 

The  tctal  extreme  settlement  to  date  is,  12-100  of  a  foot,  the  move- 
ment outwards  9-100  of  a  foot. 

The  Diver  McDonald  has  also  examined  about  40  feet  of  the  rear 
of  the  wall  at  Canal  Street,  and  found  it  in  pretty  good  order.  From 
the  rear,  however,  a  piece  of  concrete  about  3  feet  long,  12  inches  to 


8 


15  inches  wide,  and  6  inches  thick,  had  fallen  off,  and  was  brought  up 
by  him.  This  piece  is  all  that  has  been  obtained  as  yet  from  below  low 
water  mark.  It  is  a  very  poor  specimen  of  what  concrete  should  be  ; 
there  is  very  little  cement  to  be  seen  in  it,  and  it  has  so  little  cohesion 
that  it  broke  into  several  pieces  by  being  rolled  over,  and  could  be 
readily  crumbled  and  broken  to  pieces  by  the  hand.  It  is  preserved  in 
the  Canal  Street  office. 

The  King  Street  section,  180  feet  long,  was  completed  as  it  now 
stands  before  my  accession  to  the  office  ;  it  was  built  on  the  same  gen- 
eral principle  as  the  Canal  Street  section,  but  much  more  care  has  evi- 
dently been  taken  in  its  construction  and  details  than  at  Canal  Street 
section.  Diver  McDonald  was  kept  under  water,  and  tripped  every 
box  of  concrete,  and  saw  that  it  was  placed  in  its  proper  position  ;  its 
faults  and  failures  are,  therefore,  in  my  opinion,  due  to  its  being  con- 
structed on  a  wrong  principle.  This  wall  was  first  examined  in  three 
panels  of  its  face  by  diver  McDonald  ;  one  panel  near  the  southerly  end, 
one  at  the  northerly  end,  and  one  about  the  middle  of  the  section.  Mr. 
Kid,  Assistant  Engineer  in  charge  of  the  work,  also  went  down  in 
armor  and  examined  the  same  three  panels.  They  reported  the  two 
southerly  panels  smooth  and  soft,  but  at  the  northerly  panel  the  con- 
crete face  of  the  wall  had  fallen  away  from  top  to  bottom  to  a  depth 
into  the  face  of  the  wall  of  from  nine  inches  to  fifteen  inches,  and  that 
the  concrete  was  soft  where  the  face  of  the  wall  had  fallen  away.  This 
wall  having  been  recently  completed,  I  suspended  the  removal  of  the 
panels  for  several  weeks,  in  order  to  give  the  cement  time  to  set  if  it 
would  do  so. 

All  the  shutters  or  panels  on  the  rear  of  the  wall  were  then  removed, 
and  most  of  those  on  the  front.  Diver  McDonald  went  down  and 
examined  the  wall,  panel  by  panel,  coming  up  and  reporting  the  condi- 
tion of  each  ore  before  going  to  another.  He  reported  the  whole  of 
the  concrete  wall  soft,  so  that  he  could  pull  out  stones  with  his  hands, 
and  various  imperfect  places,  but  not  of  great  depth  except  in  one  or 
two  places,  including  the  above-mentioned.  I  then  sent  for  Diver  Gil- 
lihan,  employed  at  the  Battery,  and  directed  him  to  go  down  and  exam- 
ine the  whole  face  of  the  wall,  front  and  rear,  where  he  could  get  at  it. 
His  report  agrees  generally  with  that  of  McDonald.  He  describes  the 
softness  such  that  he  could  dig  into  the  wall  almost  anywhere  by 
pulling  out  the  stones  of  the  concrete  with  his  fingers,  and  that  he  did 
so  dig  in  about  eight  or  nine  inches. 

He  differs  about  the  details  of  roughness  and  holes  in  the  concrete 
wall,  and  it  must  be  remembered  that  the  diver  is  unable  to  see  any- 
thing while  under  water  (on  account  of  the  foulness  and  muddiness  of 
the  water),  and  his  examination  can  only  be  made  by  feeling  with  his 
hands  under  water  and  in  total  darkness.    A  complete  agreement  of 


9 


reports  of  examinations  made  under  such  circumstances  is,  therefore, 
not  to  be  expected. 

In  regard  to  the  plan  of  driving  piles  to  such  depth  that  their  heads 
should  be  fourteen  feet  under  low  water  mark,  by  a  follower,  and  plac- 
ing concrete  upon  them  without  cutting  off  or  squaring  their  tops,  I 
thought  it  impossible  that  any  piles  driven  so  hard  as  they  must  be,  for 
such  a  purpose,  could  be  in  a  fit  condition  to  bear  the  weight  of  the 
wall.  I  therefore  procured  a  pile-cutter  and  had  the  heads  of  the  piles 
just  driven  at  Clarkson  Street  section  cut  off,  at  a  depth  of  about  fifteen 
feet  below  low  water. 

The  result  proved  as  I  had  anticipated.  The  pile  heads,  as  they  came 
up,  when  sawed  off,  were  split  into  several  pieces,  broomed  up,  and 
damaged  so  as  to  be  unfit  for  bearing  any  weight  whatever.  A  record 
was  kept  of  each  pile  head,  showing  the  position  of  the  pile  from  which 
it  was  cut,  and  its  condition  as  to  being  split  or  broomed  up. 

The  proportions  were — one-half  in  very  bad  condition  indeed,  one- 
sixth  in  bad  condition,  and  the  remaining  one-third  of  the  whole  in  pas- 
sable order.  The  pile  heads  were  all  saved,  and  can  be  seen  at  Clark- 
son  Street,  and  also  at  Canal  Street,  south  of  New  Pier  No.  34,  where 
they  have  just  been  cut  off  in  similar  manner,  and  with  same  result. 
There  is  no  doubt  whatever  that  the  pile  heads  must  be  cut  off  in  all 
cases,  before  placing  any  weight  upon  them,  to  a  good  and  solid 
part  of  the  pile,  so  that  the  wall  may  rest  upon  a  firm  and  solid  bear- 
ing. 

The  facts  ascertained  in  my  examinations  thus  far  as  described  above, 
and  consisting  principally  of  the  softness  and  want  of  cohesion  of  the 
concrete  in  the  King  Street  section,  the  falling  off  of  whole  panels  to  the 
depth,  on  the  face  of  the  wall,  of  from  nine  inches  to  fifteen  inches  from 
top  to  bottom,  the  falling  off  of  the  lower  half  of  wall  to  the  depth,  on 
its  face,  of  two  feet  at  the  Canal  Street  section,  and  the  condition  of  the 
piece  of  concrete  brought  up  from  the  rear  of  the  Canal  Street  section, 
indicate  clearly  that  the  plan  of  building  the  wall  of  concrete  placed 
under  water  "  en  masse,"  "  in  situ,"  cannot  be  relied  upon  to  produce  a 
permanent,  stable  and  durable  wall  ;  and  I  am  under  the  necessity  ot 
recommending  at  least  the  suspension,  if  not  the  entire  abandonment, 
of  such  plan. 

No  wall  has  been  built  upon  this  plan  since  my  accession  to  office, 
except  that  part  of  the  Canal  Street  section  begun  before  I  was  appoint- 
ed, and  since  then  completed.  The  work  of  building  the  bulkhead  wall 
is  now  suspended  by  my  orders,  and  I  shall  desire  to  have  the  approval 
the  Board  of  my  action. 

In  consideration  of  the  fact  that  this  plan  of  building  the  wall  is 
highly  commended  in  the  report  of  the  late  Engineer-in-Chief  of  this 
Department,  dated  1st  June,  1875,  and  that  such  report  has  been  made 


10 


public,  and  extracts  from  it  printed  in  the  newspapers  and  in  Van  Nos- 
trand's  Engineering  Magazine,  I  beg  leave  to  suggest  to  the  Board  of 
Commissioners,  through  your  Committee,  the  propriety,  for  the  justifi- 
cation of  the  Commissioners  and  of  myself,  of  calling  to  our  assistance 
the  united  wisdom  and  experience  of  disinterested  engineers,  to  examine 
the  condition  of  that  portion  of  the  wall  referred  to  in  this  report,  and 
advise  what  remedy,  if  any,  should  be  applied  to  it. 

Very  respectfully, 

Your  obedient  servant, 


G.  S.  GREENE,  Jr., 

Engineer-in-Chief. 


11 


New  York,  Dec.  17th,  1875. 

To  the  Commissioners  of  Docks,  New  York  City  : 

Gentlemen ; — We  have  the  honor  to  submit  this  preliminary  report 
with  respect  to  the  condition  of  the  Bulk-head  Walls  at  the  foot  of 
Canal  and  King  Streets,  North  River,  upon  which  our  opinion  was 
solicited. 

The  scope  of  inquiiy  submitted  to  us  is  briefly  set  forth  in  a  com- 
munication addressed  to  us  by  His  Honor  the  Mayor,  dated  Oct.  12, 
1875,  and  is  comprised  in  the  following  extracts,  viz  : 

"  You  are  requested  to  make  an  examination  of  the  bulk-head  walls, 
"  now  partially  constructed  at  Canal  and  King  Streets,  North  River, 
"and  report  to  the  Department  of  Docks,  at  the  earliest  day  prac- 
"  ticable,  the  facts  as  to  the  condition  of  such  structure,  together  with 
"  your  opinion  as  to  their  safety  and  durability." 

"  You  are  requested  also  to  communicate  your  advice  as  to  com- 
"  pleting  such  structures,  either  with  or  without  modification  of  the 
"  plan  of  construction  ;  and  to  give  your  advice  as  to  what,  if  anything, 
"  should  be  done  with  those  structures." 

We  were  further  requested  by  your  Department  in  a  communication 
dated  the  8th  inst.,  to  express  definitely  our  opinion  "  in  regard  to  the 
system  employed  in  said  constructions." 

On  the  receipt  of  the  Mayor's  communication,  we  immediately 
entered  on  our  duties,  and  commenced  an  examination  of  the  King 
Street  and  Canal  Street  bulkheads,  the  Department  of  Docks 
having  previously  sunk  a  shaft  in  the  centre  of  the  King  Street  bulk- 
head, and  constructed  and  placed  a  three-sided  caisson  against  its  face. 
We  have  now,  with  the  aid  of  divers  made  thorough  examinations  of 
all  the  exposed  faces  of  both  bulk-heads,  the  examinations  of  important 
points  being  by  two  divers  at  different  times,  thereby  checking  their 
reports.  The  water  has  been  pumped  out  of  the  caisson  and  the  shaft 
at  King  Street,  and  we  have  made  a  personal  examination  of  the 
exterior  face  and  centre  of  the  wall.  We  have  also  had  a  shaft  sunk  in 
the  centre  of  the  Canal  Street  wall,  and  have  had  a  caisson  constructed 
there,  in  which  we  are  making  trial  of  concrete  construction  under  as 
nearly  as  possible  the  same  conditions  as  those  under  which  the  bulk- 
head was  made ;  in  fact  a  model  on  a  large  scale  of  the  wall  itself. 
When  the  concrete  shall  have  become  sufficiently  set,  the  caisson  will 
be  raised,  and  the  condition  of  the  concrete  can  be  readily  examined. 


12 


We  are  also  having  experiments  made  of  the  comparative  set  and 
strength  of  concrete  of  Portland  and  Rosendale  cements,  in  the  position 
and  under  the  circumstances  obtaining  in  the  construction  of  the  bulk- 
head. All  these  experiments  require  time  for  the  setting  of  the  cement, 
and  are  at  present  incomplete.  We  cannot  therefore  at  present  give  a 
full  answer  to  all  the  queries  proposed,  but  in  answer  to  your  first 
interrogator)',  "the  facts  as  to  the  co7iditions  of  such  structures, 
together  with  your  opinion  as  to  their  safety,  and  durability,"  we 
would  respectfully  report  that,  from  all  our  examinations,  we  find  that 
the  mode  of  construction  adopted,  in  connection  with  the  details, 
appliances  and  materials  used,  is  uncertain  in  its  results. 

We  have  found  that  the  component  parts  of  the  concrete,  have 
settled  in  layers,  or  strata  with  varying  proportions  of  cement  ;  that 
the  broken  stone  and  sand  are  in  excess  at  the  bottom  of  layer,  and  the 
cement  at  the  top  ;  that  the  cement  has  washed  out  and  deposited 
itself  as  laitance,  in  combination  with  the  soil  in  the  water  in  layers  by 
themselves,  presenting  the  appearance  of  seams  between  the  different 
layers  of  concrete,  or  of  pockets  in  spaces  in  the  concrete.  Many 
portions  of  the  wall  we  find  strong,  with  a  good  set,  but  the  faces 
almost  invariably  weak  and  the  set  imperfect  ;  but  we  do  not  find  any 
but  the  slightest  settlement  or  delignment  of  the  wall,  nor  is  it  probable 
that  either  of  these  will  increase  to  any  injurious  or  unsightly  extent, 
whilst  the  bulkheads  remain  under  their  present  conditions,  without 
back-filling.  But,  before  the  earth  filling  is  put  in  behind  the  walls* 
we  should  propose  some  further  protection  against  the  thrust  outwards 
of  the  embankment. 

Whatever  of  weakness  there  may  be  in  the  present  structures  we 
think  it  may  be  remedied  without  any  removal  of  structure  or  any 
large  expenditure.  We  would  propose  at  any  rate  to  leave  it  as  it  is 
for  the  present. 

We  do  not  wish  to  be  understood  as  condemning,  as  a  system,  the 
method  of  constructing  submarine  masonry  by  passing  mixed  concrete 
through  and  depositing  it  in  the  water.  On  the  contrary,  it  is  well 
known  that  excellent  work  can  be  executed  in  that  manner,  under 
suitable  precautions  in  respect  to  the  quality  of  the  cement  used,  the 
proportions  of  the  cement  to  the  coarse  ingredients,  the  kind  of 
apparatus  employed  in  laying  it,  and  the  care  with  which  it  is  operated. 

Our  criticisms  will  be  more  fully  set  forth  in  our  final  report,  and 
will  refer  to  the  details  of  the  method  of  construction  adopted  for  the 
Canal  and  King  Street  sections. 

Our  final  report,  which  will  give  in  full  all  the  facts  obtained  in  our 
examinations,  with  the  results  of  our  experiments,  will  be  completed 
within  the  coming  month.  In  it  we  will  endeavor  to  give  satisfactory 
answers  to  all  the  interrogations  submitted  to  us,  and  we  suggest  that 


13 


nothing  be  done  in  the  meantime  towards  completing  those  portions 
of  the  walls  for  which  the  pile  foundation  has  been  wholly  or  partially 
prepared. 

Very  respectfully, 

Your  obedient  servants, 

JOHN  NEWTON, 
Q.  A.  GILLMORE, 
WM.  E.  WORTHEN. 


14 


New  York,  Feb.  18,  1876. 
To  ti*£  Commissioners  of  Docks,  New  York  City: 

Ge7itle?7ien : — We  have  the  honor  to  submit  below  our  final  report  on 
the  bulkhead  or  quay  walls,  now  partially  constructed  on  the  water 
front  of  this  city  at  the  foot  of  Canal  and  King  Streets,  North  River, 
embracing  a  statement  of  our  views  and  opinions  upon  the  various 
questions  submitted  to  our  consideration  as  set  forth  in  the  instructions 
received  from  His  Honor  the  Mayor,  in  a  communication  dated  Oct.  12, 
1875,  and  from  your  President  in  a  letter  dated  Dec.  8,  1875. 

In  appendices  to  the  joint  report,  but  forming  a  necessary  part 
thereof,  there  will  be  found  separate  reports  or  notes  of  the  inspections 
made  by  us  individually  of  different  portions  of  these  walls. 

Those  notes  of  inspection  are  accompanied  by  such  remarks, 
explanations  and  suggestions  as  the  inspector  thought  proper  to  make, 
and  for  which  he  alone  is  responsible. 


DESCRIPTION  OF  THE  WALLS. 
Quay  Wall,  Foot  of  King  Street,  N.  R. 

In  the  monolithic  concrete  base  of  the  river  wall,  at  the  foot  of  King 
Street,  North  River,  there  were  used  1,546  barrels  Portland  cement 
— mostly  "White's,"  but  some  of  several  other  English  brands,  9,963 
cubic  feet  sand,  24,678  cubic  feet  of  concrete  stone  (trap-rock.) 

Omitting  small  fractions,  this  gives  the  proportions  by  volumn  of  1 
cement  to  1  6-10  of  sand,  and  4  of  broken  stone.  To  this  there  was 
added,  while  laying  the  concrete,'  2,403  cubic  feet  of  rubble-stone  of 
random  sizes,  varying  from  6  to  12  inches  in  longest  diameter,  distribu- 
ted as  uniformly  as  possible  through  the  mass.  The  concrete  was 
lowered  through  the  water  in  a  box  of  2  cubic  yards  capacity,  opened 
on  one  side  when  it  reached  bottom.  The  box  was  wedge-shaped, 
such  as  would  be  formed  by  cutting  a  cube  into  two  equal  parts,  by 
passing  a  plane  through  diagonally  opposite  edges.  It  had  no  cover 
on  the  top,  so  that  the  top  surface  of  the  concrete  was  subjected  to 
wash  in  its  descent  through  the  water. 

The  height  of  the  concrete  base  varied  from  9  feet  9^  inches,  to  14 
feet  9^  inches,  the  average  vertical  thickness  being  12  feet  4^  inches 


15 


This  base  is  underlaid  by  a  bed  of  rubble-stones,  but  it  rests  upon  piles 
surrounded  by  the  rubble,  as  hereinafter  described.  The  piles  are 
driven  in  eight  longitudinal  rows,  those  of  the  front  and  rear  rows 
being  placed  as  close  together  as  possible,  while  in  the  other  six  rows 
they  are  2}/z  feet  apart  between  centres.  Transversely  the  rows  are 
2.y2  feet  apart  between  the  centres  of  piles,  except  the  three  rows  in 
front,  under  the  toe  of  the  wall,  which  are  2  feet  apart  between 
centres. 

The  piles  were  driven  with  a  follower,  and,  with  the  exception  of 
those  in  the  front  row,  were  not  cut  off  after  driving.  The  heads — many 
of  them  badly  split  and  broomed  up — were  on  different  levels,  their 
average  depth  below  mean  low  water  being  13X  feet.  The  bed  of 
rubble-stones  which  surround  them  has  a  vertical  thickness  of  8  feet. 
It  was  roughly  leveled  off  when  laid,  at  an  average  depth  of  14  57-100 
feet  below  mean  low  water.  The  pile-heads  therefore  project  above  the 
rubble  an  average  distance  of  1  34-100  feet,  the  greatest  projection 
being  5  feet,  while  13  per  cent  of  them,  inclusive  of  the  front  row,  have 
their  heads  on  a  level  with  the  rubble-stone  around  them.  The  con- 
crete base,  which  was  laid  in  a  wet  caisson  constructed  after  the  foun- 
dation piles  were  driven,  is  18  feet  six  inches  thick  at  the  bottom  next 
the  rubble-stones,  and  has  a  batter  of  1  ]/z  inches  to  the  foot  on  the 
face  and  y2  inch  to  the  foot  on  the  back.  The  top  surface  is  roughly 
leveled  off  at  an  average  depth  of  2  feet  2^  inches  below  mean  low 
water. 

That  portion  of  the  wall  above  the  concrete  base,  including  the 
coping  course  not  yet  laid,  is  12  feet  high,  has  a  cut  granite  face,  laid 
in  six  courses,  of  which  five,  omitting  the  coping,  are  alternate  headers 
and  stretchers.  The  back  is  of  built-up  rubble-blocks,  and  the  heart- 
ing is  concrete  from  in  situ. 

The  granite  face  sets  back  6  inches  from  the  edge  of  the  concrete 
base,  and  has  a  batter  of  1  inch  to  1  foot  ;  the  rubble-blocks  in  rear  are 
in  two  courses,  each  4  feet  8  inches  high,  the  lower  course  being  set  so 
as  to  leave  a  concrete  berm  6  feet  wide,  thus  giving  a  thickness  of  9 
teet  to  the  base  of  this  superstructure.  The  second  course  of  rubble- 
blocks  is  set  with  an  offset  of  1  foot,  its  upper  surface  being  at  the 
level  of  the  base  of  the  coping  course.  The  granite  coping  course 
is  to  have  a  rise  of  2  feet  6  inches,  and  a  thickness  or  width  of  4 
feet. 

A  transverse  section  of  the  wall  and  foundation,  taken  where  the  bed 
of  mud  overlying  the  bearing  stratum  of  clay  is  the  deepest,  is  shown 
in  Fig.  1,  Plate  I.    Fig  2  shows  a  plan  of  the  wall. 

At  the  foot  of  the  wall,  in  front  and  in  rear,  a  bed  of  rip-rap  stones 
was  formed,  simultaneously  with  the  bed  of  rubble-stones  around  the 
pile-heads,  and  intended,  in  conjunction  therewith,  to  secure  the  piling 


16 


against  lateral  motion,  and  particularly  against  outward  thrust  from  the 
earth  rilling,  in  rear  of  the  wall. 


Diary  of  Construction. 

The  site  of  wall  was  dredged  out  between  Nov.  16  and  23,  1874, 
inclusive.    Took  out  3,600  yards  of  soft  mud. 

The  foundation  piles  were  all  driven  between  December  1,  1874, 
and  January  14,  1875,  inclusive. 

The  false  work  for  the  caisson,  including  inclined  square  piles  and 
shutters,  was  constructed  between  March  16  and  April  20,  1875,  in 
readiness  for  the  4-inch  stone  around  foundation  pile-heads,  and  the 
rip-rap  outside  in  front  and  rear.  The  piles  were  centred  8  feet  apart 
longitudinally. 

The  4-inch  stone  around  the  foundation  piles  was  all  put  in  between 
April  17  and  May  5,  1875.  The  total  quantity  was  788  cubic  yards, 
spread  over  an  area  of  146^  by  17^  feet,  giving  a  vertical  depth  of 
over  8  feet. 

The  rip-rap  outside  in  front  and  rear,  was  filled  in  and  brought  up 
simultaneously  with  the  4-inch  rubble  filling. 

Putting  in  the  rip-rap  began  April  19,  1875.  1,504  cubic  yards  of 
rip-rap  were  placed  in  front,  and  1,138  cubic  yards  in  rear. 

May  28th,  commenced  laying  concrete,  the  instructions  being  not  to 
allow  the  proportion  of  sand  to  exceed  :  cement,  1  ;  sand,  2  ;  and 
stone,  5. 

The  first  or  lower  course  was  filled  to  an  average  thickness  of  about 
2  feet,  just  covering  the  pile-heads  along  the  middle  line,  and  about  3 
feet  higher  at  the  sides  against  the  shutters,  thus  presenting  a  concave 
surface  on  top. 

The  first  course  was  laid  between  May  28th  and  June  5th,  inclusive, 
for  the  entire  length  of  the  section  equal  to  146^  feet  at  bottom, 
between  the  cross  bulkheads  at  each  end.  This  lower  course  rests 
directly  on  the  pile-heads,  and  on  the  4-inch  rubble-stones  between 
them. 

The  second  course,  about  5  feet  high,  was  begun  June  7th,  and  as 
soon  as  the  laying  cf  the  lower  course  was  finished. 

About  June  15th,  third  course,  about  5  feet,  was  begun,  and  on  that 
day,  for  a  length  of  three  panels  at  north  end,  was  carried  up  to 
within  a  few  inches  of  the  level  required  for  lower  course  of  granite. 

By  June  1 8th,  a  length  of  eleven  panels,  or  88  feet,  was  carried  up  to 
same  level. 

On  June  23d,  begun  the  4th,  or  top,  course  of  concrete  by  lowering 


17 


the  concrete  in  an  ordinary  water-bucket.  This  top  layer  was  simply  a 
leveling,  of  course,  and  was  only  a  few  inches  thick. 

June  24th,  commenced  to  set  granite  and  rubble-block  backing,  and 
the  concrete  hearting  at  north  end. 

July  3d,  the  concrete  monolith  was  finished.  The  laying  of  the  granite 
commenced  June  24th,  being  in  progress  elsewhere. 

On  July  7th,  finished  the  wall  to  present  condition,  in  readiness  for 
the  coping,  the  rubble-block  backing  and  the  concrete  hearting  having 
been  carried  up  simultaneously  with  the  face  of  the  wall. 

The  rip-rap  apron,  front  and  rear,  was  widened  after  this  date,  but  is 
not  completed  to  present  date. 

On  July  21st,  commenced  taking  up  the  shutters,  and  between  that 
date  and  September  15th,  twelve  shutters  were  taken  up  in  front  and 
seventeen  in  rear,  in  which  condition  it  now  remains. 

While  laying  the  concrete,  a  diver  was  down  nearly  all  the  time  every 
day,  and  actually  adjusted  the  position  and  tripped  the  box  for  about 
one-half  the  work. 

At  the  time  when  the  examination  was  made  in  October,  1875,  tnat 
portion  of  the  concrete  foundation  first  laid  had  been  in  place  nearly 
five  months,  while  the  different  parts  of  the  top  course  had  been  down 
from  three  and  a-half  to  four  months. 


Quay  Wall  Foot  of  Canal  Street,  N.  R. 

The  description  hereinbefore  given  of  the  traverse  form,  dimensions 
and  method  of  construction  of  the  wall  at  the  foot  of  King  Street, 
applies  also  to  the  wall  at  the  foot  of  Canal  Street,  with  the  following 
exceptions : 

1st.  The  concrete  base  is  18  feet  thick  at  bottom  at  the  level  of 
the  rubble-stones. 

2d.  The  superstructure  is  10  feet  thick  at  the  base  when  it  rests  on 
the  concrete. 

3d.  The  box  used  at  Canal  Street  for  laying  the  concrete  under 
water,  although  of  the  same  form  and  arrangement  for  tripping  as  that 
employed  at  King  Street,  was  only  half  as  large.  It  held  one  cubic 
yard,  and  like  the  other  had  no  cover  on  top. 

4th.  The  proportions  adopted  for  the  concrete  were  for  the  lower 
2-foot  layer,  1  barrel  Portland  cement,  2  of  sand,  and  4  of  broken 
stone.  For  a  portion  of  the  second  layer  (4  feet)  the  proportions  were 
1  l/z  Portland  cement,  2  sand,  and  4  broken  stone  ;  but  this  was  soon 
changed,  and  for  the  rest  of  the  entire  work  the  proportions  for  the 


18 


front  were  \  x/z  cement,  2  sand,  and  5  broken  stone  and  for  the  rear 
1%  cement,  2  sand,  and  5  broken  stone. 

Fig.  1,  Plate  II.,  shows  a  transverse  section  of  the  Canal  Street  wall 
and  pile  foundation,  taken  at  a  point  where  the  bed  of  mud  is  the 
deepest,  through  which  the  piles  have  to  pass  before  they  reach  a 
holding  stratum.  Figs.  2  and  3  show,  respectively,  a  plan  and  eleva- 
tion of  the  wall. 


Diary  of  Construction. 

September  11,  1874,  commenced  dredging  the  site.  October  6, 
1874,  finished  dredging. 

During  this  interval,  there  were  removed  1,400  cubic  yards  of  stone 
(old  crib  from  Pier  42^),  and  9,050  cubic  yards  of  mud,  giving  an 
average  low  water  depth  of  20  feet. 

October  20,  1874,  commenced  driving  foundation  piles,  spaced 
exactly  like  those  of  the  King  Street  wall.  The  .front  row  was  cut  off 
by  November  16th  at  the  level  of  14  feet  inches  below  mean  low 
water,  all  the  piles  in  the  eight  rows  being  driven  with  a  punch  to 
different  levels,  as  at  King  Street. 

By  December  4,  1874,  all  the  square  piles  for  false  work  were  driven 
for  193  lineal  feet  of  wall,  and  239  cubic  yards  of  rip-rap  stone  placed 
in  front  under  and  a  little  to  the  south  of  Pier  34,  and  466  cubic  yards 
of  4-inch  stone,  and  98  cubic  yards  of  smaller  stone  placed  between 
the  piles,  to  an  average  depth  of  4  feet.  It  was  rammed  by  a  long- 
handled  rammer,  worked  by  three  or  four  men  above. 

December  24,  1874,  commenced  concreting  55  feet  south  of  south 
line  of  Pier  34,  and  worked  up  to  north  line  of  Pier  34,  with  the  lower 
2-foot  layer. 

January  n,  1875,  finished  this  first  layer.  March  17,  1875, 
commenced  second  layer  4  feet  thick,  and  followed  it  with  another 
4-foot  layer,  and  on  April  5th,  commenced  with  the  top  or  trimming 
layer  of  2  feet. 

May  4th,  commenced  laying  first  course  of  stone  ;  and  on  May  22d, 
finished  100  lineal  feet  of  wall,  except  the  coping  course. 

This  portion  extends  from  north  side  of  Pier  34  100  feet  south,  rack- 
ing off  in  offsets  at  each  end  for  future  construction. 

The  coping  course  has  not  yet  been  set,  and  will  not  be  required  under 
Pier  34,  which  covers  90  feet  in  length  of  the  wall. 


North  of  Pier  34. 
By  July  9,  1875,  the  portion  of  the  Canal  Street  wall,  north  of  Pier 


19 


34.  was  got  ready  for  laying  the  lower  2-foot  course  of  concrete  around 
the  pile-heads. 

Between  July  9  and  26,  1875,  placed  concrete  base  for  50  lineal 
feet  of  wall  in  extension,  north  of  Pier  34,  ready  for  stone.  July  27th, 
commenced  laying  stone  on  this  50  lineal  feet. 

By  August  20,  1875,  the  wall  was  finished  to  its  present  condition, 
the  coping  being  omitted  ;  the  portion  north  of  Pier  34,  being  112  feet 
long  on  the  bottom,  and  87  feet  long  on  the  top  of  fifth  (E)  course. 

For  that  portion  of  the  concrete  base  south  of  the  north  side  of  Pier 
34,  only  Knight,  Bevan  &  Sturges's  cement  was  used. 

For  the  50  feet  north  of  the  norch  side  of  Pier  34,  the  greater  por- 
tion was  White's,  with  Knight,  Bevan  &  Sturges's  on  the  face  of  wall. 

For  the  additional  62  feet  north  end,  Burham  &  Gillingham's  cement 
was  used,  with  probably  some  of  White's. 

At  the  time  of  inspection,  the  age  of  the  concrete  in  that  portion  of 
the  base  under  and  south  of  Pier  34,  ranged  from  six  and  a-half  to  ten 
months,  while  the  part  last  laid  on  the  north  end  of  the  section  was  from 
two  and  a-half  to  three  months  old,  before  the  inspection  was  com- 
pleted. 

In  order  to  test  the  qualities  of  Rosendale  and  Portland  cement  under 
the  same  circumstances  of  exposure,  mixed  with  different  proportions  of 
sand  and  broken  stone,  eight  varieties  of  concrete  were  deposited  in 
casks  under  water  January  3d,  and  taken  out  and  examined  January 
2f,  1  S76. 

The  casks  were  of  forty-five  gallon  capacity,  and  were  pierced  with 
i-inch  auger  holes  on  all  sides,  the  holes  being  3  inches  apart  between 
centres  horizontally,  and  from  3  to  5  inches  apart  vertically.  The  bot- 
toms were  pierced  in  a  similar  manner,  the  holes  being  3  inches  apart 
between  centres  both  ways.  Four-inch  rubble-stones,  of  the  kind  used 
around  the  pile-heads  under  the  Canal  and  King  Streets  walls,  were 
then  put  in  the  bottom  of  each  cask  to  the  depth  of  9  to  10  inches,  and 
they  were  then  set  in  the  water  alongside  of  the  wall  at  the  foot  of  Canal 
Street,  so  as  to  be  entirely  submerged,  the  tops  of  the  casks  being  about 
6  inches  below  the  surface  of  the  water.  The  concrete,  as  soon  as 
mixed,  was  taken  up  with  shovels  and  deposited  in  the  several  casks 
until  they  were  filled,  one  after  the  other.  The  shovelful  of  concrete 
was  in  each  case  passed  through  the  water  until  it  reached  the  place 
of  deposit,  when  it  it  was  tipped  so  as  to  allow  the  concrete  to  slide  off. 

In  this  condition  they  were  left  for  eighteen  days,  constantly  sub- 
merged, with  the  exception  of  two  or  three  occasions,  when  they  were 
partly  out  of  water  for  a  short  time.  On  January  13th,  at  3  P.  M.,  when 
the  temperature  was  several  degrees  below  the  freezing  point,  the  tide 
fell  about  18  inches  below  the  tops  of  the  casks. 

Subsequently,  their  tops  were  again  exposed,  for  about  6  inches. 


20 


On  the  eighteenth  day  after  immersion,  they  were  all  raised,  opened  on 
the  sides  by  removing  several  staves,  and  carefully  inspected  by  cutting 
into  the  body  of  the  concrete.  The  kinds  and  proportions  of  materials 
used  in  each  cask,  and  the  condition  of  the  concrete  at  the  time  of  ex- 
amination are  given  below. 

The  Portland  cement  was  the  kind  used  in  the  foundations  of  the 
Canal  and  King  Streets  walls,  and  of  good  quality. 

The  Rosendale  cement  was  manufactured  by  F.  O.  Norton.  It  was 
selected  from  his  stock  on  hand,  some  of  it  being  rather  quicker  set- 
ting than  the  rest,  though  not  conspicuously  so. 

Number  One. 

Portland  cement,  measured  dry   3  volumes. 

Sand,  measured  damp   5 

Broken  stone   10  " 

This  concrete  was  in  all  respects  like  the  best  quality  used  in  the 
foundations  of  the  Canal  Street  and  King  Street  walls. 

On  examination,  the  cement  and  sand  were  found  to  be  badly  washed 
out  from  the  broken  stone  on  all  sides  next  the  barrel,  and  in  the  lower 
portions  next  the  rubble-stones,  leaving  numerous  voids  in  the  mass. 

Considerable  sand  and  cement  were  found  among  the  rubble  at  the 
bottom  of  cask,  and  some  had  evidently  washed  out  through  the 
auger  holes.  Where  not  washed  out,  the  set  of  the  concrete  was  pretty 
good.  Near  the  top  of  the  cask  the  concrete  was  free  from  voids,  and 
of  much  better  quality  than  below.    The  set  was  quite  hard  on  top. 

Number  Two. 

Portland  cement,  measured  dry   2  volumes. 

Common  lime,  slaked  to  powder   1]^,  '* 

Sand,  measured  damp   5  " 

Broken  stone  10  " 

The  cement  and  sand  were  badly  washed  out  all  around  next  the 
cask,  and  also,  to  some  extent,  but  not  so  badly,  through  the  mass. 
Poor  set  next  the  cask,  but  good  set  in  middle,  away  from  the  wash. 
Very  little  mortar  left  among  the  stone  next  the  cask,  for  about  3  inches 
all  around.  Set  somewhat  better  than  in  Number  One,  and  sand  re- 
tained better  in  the  heart  of  the  mass. 

Number  Three. 

Rosendale  cement,  dry  iy2  volumes. 

Damp  sand   5 

Broken  stone     10 

Cement  and  sand  washed  out  around  outside,  next  the  cask,  but  not 


21 


badly.  Also,  washed  out  for  so.ne  distance  above  the  large  rubble- 
stones.  Very  little  set,  except  in  the  upper  portions.  Too  much  sand 
was  used  in  the  mortar. 

Number  Four. 

Rosendale  cement,  dry   4  volumes. 

Common  lime,  slaked  to  powder   1%. 

Damp  sand   5  " 

Broken  stone  10 


Main  bulk  of  concrete  good,  and  no  washing  out  of  the  cement  and 
sand  except  a  very  little  at  bottom  next  the  rubble-stones.  The  mor- 
tar retained  its  constituents  throughout  the  mass,  and  there  were  no 
voids,  except  at  bottom  as  above  noted.  Good  adhesion  of  mortar  to 
stone,  and  a  very  good  set.    Concrete  satisfactory. 


Number  Five. 

Rosendale  cement,  quick-setting   5  volumes. 

Damp  sand   5  - 

Broken  stone  10  " 


The  same  remarks  apply  to  this  concrete  as  to  Number  Four,  except 
that  it  had  set  a  little  harder,  and  on  that  account  might  be  pronounced 
a  little  better. 

Number  Six. 

Slow-setting  Rosendale  cement,  dry   .  5  volumes. 

Damp  sand   5  " 

Broken  stone  10  " 


Very  little  sifting  or  washing  out  of  cement  and  sand,  and  very  good 
concrete.    The  set  was  satisfactory,  and  the  mass  well  held  together. 


Number  Seven. 

Slow-setting  Rosendale  cement,  dry   4  volumes. 

Common  lime  slaked  to  powder   1%  " 

Damp  sand   5  " 

Broken  stone    10  " 


Very  little  cement  and  sand  washed  out,  and  that  only  close  to  sides 
of  cask,  and  directly  next  the  rubble-stones.  No  voids  in  concrete 
elsewhere. 

Good  adhesion  of  mortar  to  stones,  and  very  good  concrete  as  a 


22 


whole.  Set  not  quite  so  good  as  in  Number  Five.  Cask  well  filled 
out  all  around. 

Number  Eight. 

Slow-setting  Rosendale  cement,  dry   4  volumes. 

Quicklime  (not  slaked)  -   1  " 

Damp  sand   5  " 

Broken  stone  10 


The  cement,  sand  and  lime  remained  well  mixed,  and  there  was 
little,  if  any,  washing  out  from  among  the  stones.  Some  traces  of  lime, 
but  no  sand,  among  the  rubble-stones  below.  There  was  very  little 
set  in  the  concrete. 

The  best  out  of  these  eight  kinds  of  concrete  are  Numbers  Four, 
Five,  Six,  and  Seven.  There  being  very  little  difference  in  the 
hydraulic  activity  of  the  Rosendale  cement  used,  Number  Four  should 
give  the  same  result  as  Number  Seven,  and  Number  Five  the  same 
as  Number  Six.  So  little  difference  was  exhibited  among  these  four 
specimens,  that  the  propriety  of  cheapening  the  concrete  by  replac- 
ing a  portion  of  the  cement  with  common  lime  cannot  be  doubted. 


DESCRIPTION  OF  CAISSON. 

[See  Plate  III.] 

It  was  judged  expedient  by  committee  that  a  large  box  or  caisson 
should  be  constructed,  and  sunk  beneath  the  water,  in  which  should  be 
deposited  the  same  materials  as  those  used  in  the  construction  of  the 
wall — in  the  same  proportions,  and  under,  as  nearly  as  possible,  the 
same  conditions — making  a  fac  simile  of  the  lower  part  of  the  wall, 
which  could  afterwards  be  raised  out  ot  the  water  and  examined. 

The  size  of  the  box  was  limited  by  the  capacity  of  the  largest 
derrick,  and  the  total  weight  of  box  and  contents  was  estimated  at 
from  80  to  85  tons.  The  interior  area  of  the  box  was  about  10  feet 
square,  but  the  platform  on  which  it  was  supported  was  16  feet  square. 
This  platform  was  composed  of  timber,  12'  x  12',  placed  about  2  and 
3  inches  apart,  extending  lengthways  of  the  wall.  On  these  timbers 
there  was  a  2-inch  tight  plank  platform.  And  on  the  outer  edges  of 
the  timbers  there  were  timber  sides  also  12'  x  12',  3  timbers  high  on  all 
sides,  making  a  complete  box,  about  3  feet  high  ;  there  were  small 
interstices  between  the  timbers,  crossing  the  lower  timbers.  On  the 
other  sides,  where  the  timber  sides  were  parallel  with  the  bottom 
timbers,  the  central  timbers  were  cut  to  about  7  feet  in  length,  and 


23 


placed  in  the  centre  of  the  sides,  so  as  to  leave  apertures  of  3  feet  by 
1  foot  at  each  end.  These  sides  corresponded,  when  in  position,  with 
the  river  and  rear  faces  of  the  wall,  where  there  should  be  more  circu- 
lation through  the  broken  stone  base,  than  at  the  other  sides,  which 
represented  lines  of  cross  sections  of  the  wall. 

Within  the  timber  sides,  furring  blocks  were  spiked  of  about  1  foot 
in  width,  to  which  were  nailed  3  2-inch  planks,with  about  1  inch  inter- 
stices between  them.  These  planks  formed  a  box  about  10  feet  square 
and  3  feet  high,  and  enclosed  the  space  which  was  fo  be  filled  with 
broken  stone.  Inside  this  box  were  set  piles  of  12  to  15  inches  diame- 
ter, and  from  3  feet  6  inches  to  4  feet  6  inches  in  length  ;  the  front  row 
— that  is,  those  which  were  to  be  on  the  front  line  of  wall  or  river-side, 
were  8  in  number  and  placed  almost  close  together,  and  were  sawed 
off  to  an  uniform  height  of  4  feet  above  platform.  Between  this  row 
and  the  next  2  in  the  rear,  the  spaces  between  the  piles  were  about  18 
inches,  and  between  the  3d  and  4th  or  last  row,  the  space  was  about  2 
feet  6  inches.  The  2d,  3d  and  4th  rows  consisted  of  4  piles,  each  of 
various  heights,  some  with  sawn  tops,  others  as  they  had  been  cut  off 
from  piles  already  driven  and  left  broomed  at  the  top.  These  piles  were 
placed  laterally  about  2  feet  6  inches  between  centres,  and  all  were 
strongly  spiked  to  the  platform  with  little  short  braces,  about  6  inches 
long  at  the  bottom.  There  was  no  connection  between  the  piles  ;  the 
spaces  were  left  entirely  free  for  the  reception  of  the  broken  stone.  In 
front  of  the  front  row  of  piles,  there  was  a  space  of  about  2  inches 
between  the  piles  and  the  planking,  at  the  rear  and  sides  about  6  inches. 

Above  the  3-foot  box,  a  tight  plank  box  was  made  about  6  feet  high, 
with  a  sloping  face  in  front  corresponding  to  that  of  the  wall.  At  the 
sides  and  rear  the  faces  were  vertical. 

The  lower  timbers  were  securely  bolted  to  the  side  timbers,  and  4 
strong  eye-bolts  extended  down  through  the  side  and  bottom  timbers. 
The  frame  was  rigid  ;  and  by  chains  attached  to  the  eye-bolts,  the 
caisson  could  be  readily  raised  and  deposited  in  place. 

The  position  chosen  for  sinking  the  caisson  was  on  the  line  of  the 
Canal  Street  dock,  nearly  opposite  the  mouth  of  the  Canal  Street  sewer. 
The  limits  of  our  investigations  were  the  King  Street  and  Canal  Street 
docks,  to  determine  whether  these  structures  were  reliable,  and  if  not, 
what  should  be  the  form  of  the  extension  of  these  structures,  on  the 
foundations  already  prepared.  At  Canal  Street,  the  pile  foundation 
was  already  in  and  cut  off  nearly  level,  affording  a  secure  base  for  the 
support  of  the  caisson.  No  so  convenient  a  site  could  be  secured  at 
King  Street,  and  accordingly  the  caisson  was  loaded  with  broken  stone 
and  sunk  at  Canal  Street,  with  its  sloping  face  toward  the  river,  and 
on  the  line  of  the  wall.  The  broken  stone  was  placed  in  under  the 
direction  of  Mr.  Radenhurst,  the  Engineer,  who  had  had  charge  of  the 


24 


construction  of  the  Canal  Street  dock,  and  levelled  off  to  the  height  of 
about  3  feet  above  the  platform.  Word  was  then  sent  to  the  Com- 
mittee of  the  readiness  for  the  deposit  of  the  concrete.  The  Committee 
attended  November  12,  1S75,  and  there  were  present  a  portion  of  the 
time,  Gen.  Graham,  the  former  Engineer,  and  Mr.  G.  S.  Greene,  Jr., 
present  Engineer  of  the  Department  of  Docks. 

Mr.  Radenhurst  took  charge  of  the  work,  assisted  by  the  same  fore- 
man and  many  of  the  workmen,  who  had  previously  been  employed  in 
the  construction  of  the  Canal  Street  dock.  The  Committee  themselves 
gave  no  directions  as  to  the  detail  of  the  preparation  of  the  material, 
or  the  manner  of  the  deposit,  but  took  full  notes  of  the  work  as  it  was 
done.  Their  directions  to  Mr.  Radenhurst  were  to  make  as  nearly  a 
fac  simile  of  the  concrete  wall  of  the  dock  as  possible,  using  the  same 
proportions  of  cement,  sand  and  broken  stone,  the  same  trip-bucket, 
and  discharging  the  same,  with  the  usual  fall  through  the  water.  On 
the  I2:h,  14  batches  ot  concrete  were  deposited,  consisting  of  one 
barrel  of  Portland  cement,  two  barrels  of  sand,  four  barrels  of  broken 
stone,  each.  This  corresponded  with  proportions  in  the  first  layer  of  con- 
crete in  the  wall,  which  rilled  in  around  and  above  the  head  of  the 
piles.  Soundings  were  made  by  Mr.  Radenhurst  of  this  layer  after  it 
was  deposited,  and  the  accompanying  sections  furnished  to  the  Com- 
mittee. 

This  layer  was  left  to  set  till  December  13th,  when  a  second  layer 
of  six  batches,  consisting  of  1  %  barrel  of  Portland  cement,  2^  barrels  of 
sand  and  5  barrels  of  broken  stone,  each  ;  and  on  December  14th, 
eight  batches  of  the  same  proportions,  as  on  the  13th,  were  deposited. 

On  November  12th,  the  temperature  of  the  water  in  the  caisson  was 
51 0  Fahrenheit,  and  of  the  fresh  water  with  which  the  concrete  was 
made,  480.  December  13th,  the  water  in  caisson  was  380,  and  the 
fresh  water  was  heated  to  730  Fahrenheit ;  on  the  14th,  nearly  the 
same  temperatures  were  obtained. 

The  caisson  was  left  undisturbed  till  January  17,  1876,  when  the 
100-ton  derrick  was  brought  from  the  Battery,  and  the  caisson  was  safely 
raised  and  deposited  on  the  timber  dock  adjacent.  The  committee 
commenced  the  stripping  off  the  plank  and  timber  sides  on  the  after- 
noon of  the  same  day,  exposing  the  rear  face,  which  was  photographed 
on  the  18th  (1) ;  the  loose  stones  at  the  bottom  were  then  removed, 
and  photograph  (2)  taken  ;  subsequently  the  planking  and  the  timbers 
of  the  other  sides  were  removed  and  photographs  taken  on  the  20th, 
sufficient  to  show  the  condition  of  the  concrete  as  it  appeared  on  the 
removal  of  the  sides  of  the  box,  and  of  the  interior  after  it  was  broken 
into.  The  photographs  (1  to  6  inclusive)  are  herewith  submitted,  with 
explanatory  references. 

The  faces  of  concrete,  as  marked  on  the  photographs,  designate  their 


26 


ity.  There  were  layers  of  concrete  made  up  of  varying  proportions  of 
sand  and  cement,  but  sand  always  in  excess  ;  some  with  so  little  cement 
as  hardly  to  be  considered  concrete,  and  others,  where  the  set  had 
become  very  good,  and  could  only  be  detached  in  masses.  The  first 
layer  around  the  head  of  the  piles  in  the  interior  of  the  caisson  had  a 
very  fair  set,  but  the  layer  directly  above  it,  deposited  December  13th, 
and  from  6  to  9  inches  thick,  was  by  far  the  best  concrete  in  the 
mass. 

As  a  whole,  although  there  is  in  the  mass  some  extremely  fair  and 
well-set  concrete,  it  is  not  sufficiently  homogenous  to  be  considered  a 
monolith  ;  and  the  exterior  faces — where,  in  construction,  they  would  be 
most  exposed — are  weakest  and  worst.  When  cement  like  this  is  used, 
and  the  concrete  deposited  in  water,  there  seems  to  be  a  tendency  in 
the  cement  to  separate  from  the  mass,  and  the  smaller  the  mass  in  which 
it  is  deposited  and  the  deeper  the  water  in  which  it  is  discharged  from 
the  bucket,  the  greater  the  likelihood  of  separation.  The  deposit  of 
each  day  is  marked  by  a  layer  or  seam,  which  probably  might  be 
removed  by  washing,  but  has  not  been  in  the  construction  of  which  we 
have  made  an  examination. 

It  was  our  instruction  to  make  the  caisson,  as  near  as  possible,  a 
sample  of  the  wall  as  built,  and,  on  its  face,  it  exhibits  the  same  denud- 
ing of  the  outer  row  of  piles,  the  same  seams,  and  sometimes  larger 
deposits  of  washed  cement,  dry  and  loose  stones,  and  sand  in  excess. 
In  the  interior,  the  caisson  exhibits  seams  greater  in  width  than  those 
in  the  Canal  Street  dock  shaft,  with  deposit  of  sewerage  ;  but  the 
concrete  around  the  head  of  the  piles,  and  directly  above  the  first  seam, 
is  of  the  same  general  character  in  both 


Replies  to  Official  Communications. 

Our  original  instructions,  as  contained  in  a  letter  from  His  Honor  the 
Mayor,  bearing  date  Oct.  12,  1875,  are  as  follows  :  "  You  are  requested 
to  make  an  examination  of  the  bulkhead  wall  now  partially  constructed 
at  Canal  and  King  Streets,  North  River,  and  to  report,  to  the  Depart- 
ment of  Docks  at  the  earliest  day  practicable,  the  facts  as  to  the  condition 
of  such  structures,  together  with  your  opinion  as  to  their  safety  and 
durability. 

"  You  are  requested  also  to  communicate  your  advice  as  to  completing 
such  structures,  either  with  or  without  modifications  of  the  plan  of  con- 
struction ;  and  to  give  your  advice  as  to  what,  if  anything,  should  be 
done  with  those  structures. 

"  For  general  details  of  plans,  and  for  the  proper  facilities  to  enable 


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27 


you  to  prosecute  your  examination,  you  are  referred  to  the  Department 
of  Docks,  and  are  requested  to  communicate  with  the  President  and 
Commissioners  of  that  Department,  and  to  act  under  their  directions." 

Agreeably  to  this  request,  we  waited  on  the  President  and  Commis- 
sioners of  the  Department  of  Docks,  and  all  the  records  of  the  De- 
partment, with  reference  to  the  construction  of  the  bulkheads,  were 
submitted  to  us,  and  the  Chief  Engineer,  Mr.  George  S.  Greene,  Jr., 
was  directed  to  furnish  us  every  facility  in  our  investigations. 

The  former  Engineer-in-Chief,  Gen.  Charles  K.  Graham,  sent  us 
copies  of  his  report  on  these  structures,  and  from  time  to  time  has  cor- 
dially met  us,  and  explained  the  design  of  the  work  and  the  directions 
given  for  its  prosecution.  The  Assistant-Engineers,  Messrs.  Raden- 
hurst  and  Kid,  having  had  immediate  charge  of  these  constructions, 
have  assisted  at  our  examination  and  experiments,  and  given  us  the 
details  of  construction. 

We  preface  our  report  with  a  brief  sketch  of  these  structures,  drawn 
from  the  records  of  the  Department  and  from  reports  and  excerpts  from 
the  diaries  of  the  engineers  in  charge  of  construction.  We  append  the 
facts  obtained  from  our  own  examinations. 

The  examinations  of  the  exterior  faces  of  the  wall  could  only  be 
done  by  divers ;  two  were  employed,  neither  in  the  service  of  the 
Department,  and  the  reports  of  one  were  checked  by  those  of  the 
other.  Every  panel  in  the  front  and  rear  of  the  King  and  Canal  Street 
walls,  which  was  exposed,  was  examined,  holes  were  drilled,  and  speci- 
mens of  material  brought  up  for  our  inspection. 

We  have  had  a  caisson  constructed  and  submerged,  in  which  con- 
crete has  been  deposited,  of  the  same  proportions  of  cement,  sand  and 
'  broken  stone  as  that  of  the  bulkhead  at  Canal  Street. 

This,  after  an  allowance  for  the  setting  of  the  material,  has  been 
raised  and  deposited  on  the  dock,  as  a  probable  specimen  of  what  the 
bulkhead  wall  might  be. 

We  have  had  shafts  sunk  in  the  King  Street  and  Canal  Street  walls, 
for  a  personal  inspection  of  their  interior  condition  ;  and  a  three-sided 
caisson  has  been  fitted  to  one  of  the  panels  of  the  King  Street  dock, 
and  freed  from  water,  to  give  us  the  same  partial  inspection  of  its  face. 

We  have  made  experiments  on  different  kinds  of  cement,  in  different 
proportions  of  cement,  sand  and  broken  stone,  deposited  in  submerged 
barrels,  with  reference  to  the  material  to  be  recommended  in  future 
construction. 

All  the  above  are  given  fully  in  detail.  It  remains  for  us  to  make  our 
deductions  from  facts  thus  obtained  and  reply  to  the  request  of  His 
Honor  the  Mayor. 

ist.  "  As  to  the  safety  and  durability  of  these  structures."  In  our 
opinion,  as  structures  we  cannot  consider  them  as  safe  and  durable  in 


•is 

their  present  condition,  nor  with  the  further  precautions  intended  by 
their  designer  ;  and  for  the  following  reasons,  viz. : 

The  foundation  is  composed  of  8  rows  of  piles  driven  vertically,  the 
front  and  rear  rows  being  set  as  close  together  as  possible,  with  a  layer 
of  broken  stone — intermediate — between  the  piles,  and  aprons  of  sim- 
ilar stone  in  front  and  rear,  as  already  described.  The  length  of  the 
piles  under  the  King  Street  bulkhead  averages  about  50  feet,  measured 
from  the  "  formation  level,"  at  the  bottom  of  the  concrete  base.  The 
upper  stratum  is  represented  as  "dock  mud,"  the  lower  20  feet  as 
"tenacious  mud,"  and  the  base  on  which  the  pile  rests  as  "  clay  and 
sand." 

The  length  of  the  piles  beneath  the  Canal  Street  bulkhead  is  30  feet, 
measured  from  the  same  level  as  above,  resting  on  the  same  base  of 
clay  and  sand,  with  a  depth  of  "  tenacious  mud  "  overlying  of  from  6 
to  19  feet,  and  an  upper  stratum  of"  dock  mud." 

We  are  obliged  to  assume,  for  the  sake  of  safety,  that  the  base  of 
these  walls  is  virtually  somewhere  within  the  stratum  of  "  tenacious  mud  " 
and  near  the  "  clay  and  sand  "  base.  We  do  not  concede  that  the  aprons 
of  broken  stone  or  rip-rap,  placed  at  the  level  of  the  pile-heads,  have 
the  effect  to  transfer  the  base  of  the  structure  from  the  lower  to  the 
upper  ends  of  the  piles.  A  constant  pressure  from  behind  may  move 
out  the  entire  mass  of  stone  by  sliding  it  forward  in  the  layer  of  "  dock 
mud  "  on  which  it  rests  ;  under  this  assumption,  it  would  not  be  safe  to 
rill  behind  these  walls  with  earth  to  the  level  of  the  top  of  the  coping. 
Your  late  Engineer-in-Chief,  Gen.  Graham,  in  order  to  relieve  this 
thrust  from  the  back-filling,  drove  seven  rows  of  piles,  spaced  feet 
between  centres  in  the  rear  of  the  wall,  and  we  understand  it  was 
his  intention  to  stay  the  tops  of  these  piles  by  ledger  plank,  strongly 
spiked,  just  above  low  water  level.  Although  this  system  of  piles 
might  answer  a  temporary  purpose,  we  do  not  consider  this  method 
sufficient  to  relieve  the  thrust  and  insure  the  safety  and  durability  of 
the  wall. 

Of  the  imperfections  of  the  mass  concrete  around  and  above  the 
piles,  the  details  are  given  in  the  divers'  reports  and  examinations,  it  is 
only  necessary  to  state  its  condition  in  a  general  way. 

The  river  face  of  the  King  Street  bulkhead  has  fallen  off  badly  and 
caved  under  at  the  toe  in  many  places,  denuding  the  top  of  the  first  row 
of  piles,  virtually  reducing  the  base  of  the  wall  to  16 y2  feet ;  still  there 
is  a  fair  breadth  of  wall  remaining,  ample  to  resist  all  crushing  strains, 
were  there  no  other  weaknesses  of  construction. 

At  Canal  Street,  the  river  face  is  not  as  much  exposed  as  at  King 
Street.  Many  of  the  "shutters  "  are  still  in,  and  rip-rap  and  broken 
dockage  cover  much  of  the  lower  surfaces.  When  exposed,  the  face 
was  found  to  be  generally  of  an  imperfect  set,  with  well-developed  soft 


29 


seams,  some  of  considerable  width,  and  extending  deeply  into  the  body 
of  the  work.  But  the  concrete  of  the  interior,  as  tested  by  a  single 
shaft  at  both  places,  is  better  at  Canal  than  at  King  Street.  The  back 
of  the  wall  at  both  places,  considering  its  position  without  exposure  to 
wash,  is  fair. 

Besides  the  elements  of  uncertainty  in  both  bulkhead  constructions, 
arising  from  imperfect  set,  and  separation  of  the  component  parts  of  the 
material,  soft  seams  and  abrasion  of  face,  there  is  another  in  the  condi- 
tion of  some  of  the  pile-heads  in  the  mass  of  concrete.  Whilst  admit- 
ting the  value  of  the  extension  of  the  piles  up  into  the  mass,  and  the 
binding  and  uniting  qualities  of  the  concrete  among  the  piles,  still, 
where  a  pile  has  been  driven  by  a  follower,  and  the  top  of  the  pile  left 
broomed  and  broken,  the  obvious  inference  must  be,  that  the  head  of 
the  pile  is  injured  for  an  insistent  weight,  and  from  the  overhang  of  the 
head,  the  concrete  may  fail  to  enclose  the  bod}  of  the  pile  below\  As 
an  apparent  evidence  of  this,  when,  in  the  shaft  at  Canal  Street,  the  top 
of  a  pile  was  reached,  the  water  flowed  in  so  freely  around  the  pile  that 
the  work  was  suspended. 

Above  the  lower  mass  concrete,  the  granite  river  face  and  beton- 
block  backing  with  concrete  mass  hearting  are  well  massed,  strong  and 
permanent. 

Whilst  thus  giving  the  general  imperfections  of  the  mass  concrete, 
its  falling  off  from  what  was  intended  to  be  its  composition,  and  the 
uncertainty  of  the  elements  on  which  calculations  for  stability  may  be 
based,  it  is  proper  to  state  that  there  is  now  no  disturbance  of  alignment 
in  the  visible  structure,  no  cracks  that  show  dangerous  settlement. 

Having  decided  against  the  stability  and  durability  of  these  structures, 
we  now  proceed  to  comply  with  the  second  request  of  His  Honor  the 
Mayor—"  to  communicate  our  advice  as  to  completing  such  structures, 
"  with  modifications  of  the  plan  of  construction,  and  to  give  advice  as  to 
"  what  should  be  done  with  those  structures." 

Where  the  granite  wall  is  complete,  with  the  exception  of  coping,  we 
advise  that  the  coping  be  laid  both  at  Canal  and  King  Streets.  Where 
only  the  piles  have  been  driven  for  the  foundation,  we  advise  that  the 
first  three  rowrs  of  piles,  front  and  rear,  and  intermediate  piles,  sufficient 
for  the  support  of  headers,  hereafter  described,  should  be  cut  off  at  an 
uniform  level  from  a  permanent  stage.  We  recommend  the  exterior 
faces,  both  front  and  rear,  and  headers  of  the  foundation  courses,  to  be 
made  of  rubble-blocks  as  prepared  by  Gen.  Graham,  or  Beton-blocks. 
of  width  sufficient  to  bear  on  the  the  three  rows  of  piles,  front  and  rear 
for  the  stretchers  ;  and  two  transverse  rows  for  the  headers,  to  have  suf- 
ficient rise  or  height  to  complete  the  foundation  to  the  level  of  the  A 
course  in  two  courses.  Both  courses  to  be  alternately  headers  and 
stretchers ;  stretchers  in  such  lengths  as  may  be  best  adapted  to  the 


30 


derricks,  say  from  9  to  12  feet  long  ;  headers  to  extend  through  both 
walls.  The  lower  face  of  upper  headers  between  the  walls  to  be  cham- 
fered at  angles  of  45 0  on  each  side  to  an  edge  at  the  centre,  so  that 
there  may  be  no  surface  sheltered  from  the  mass  concrete  hearting  as 
deposited.  The  first  layer  of  hearting  on  top  of  the  piles  to  be  of  bags 
tilled  with  concrete  in  courses,  which  will  adjust  themselves  around  and 
enclose  the  heads  of  the  piles,  and  make  a  strong  and  secure  base. 
Above  the  bags,  the  space  to  be  rilled  in  with  mass  concrete.  As  each 
course  of  upper  headers  makes  a  sort  of  box,  the  concrete  is  to  be  pre- 
pared in  mass  sufficient  to  fill  this  space,  and  deposited  at  once  by  a 
trimie. 

Of  the  material  and  proportions  of  which  the  blocks  should  be  made, 
we  see  no  reason  to  alter  the  proportions  and  material  already  adopted  ; 
but  for  the  hearting,  we  recommend  the  use  of  Rosendale  cement, 
quick-setting,  instead  of  Portland,  with  the  addition  of  a  little  slaked 
lime  in  proportions  4  volumes  cement,  \%  common  lime  slaked  to  pow- 
der, 5  sand,  10  broken  stone. 

With  regard  to  the  wall  above  the  concrete  base  as  above,  we  recom- 
mend no  change  of  the  present  construction. 

To  resist  the  thrust  of  the  back-filling  we  recommend  that  1 1  rows 
of  vertical  piles,  spaced  to  3-feet  centres,  be  driven  in  the  rear  of  the 
wall  at  Canal  Street,  and  13  rows  at  King  Street,  with  rows  of  interme- 
diate inclined  piles  ;  the  inclined  piles  to  be  driven  at  an  inclination  of 
3"  horizontal  to  12  vertical,  each  row  to  be  3  in  number;  the  first,  or 
nearest  the  wall,  to  be  so  driven  that  the  foot  will  rest  near  to  and  in 
the  rear  of  the  foot  of  the  rear  row  of  piles  beneath  the  wall ;  the  3d 
pile-head  to  be  on  a  line  with  the  last  row  of  vertical  piles — that  is,  the 
nth  and  13th  from  the  wall,  as  above.  That  a  string-piece  be  securely 
bedded  on  the  rear  projection  of  the  concrete  mass,  or  beton-blocks. 
That  the  piles  be  cut  off  at  a  suitable  level,  so  that  their  caps,  notched 
to  receive  the  head  of  the  piles,  may  rest  on  this  string-piece,  the  caps 
to  be  trunailed  to  the  string-pieces  and  to  the  piles  ;  the  planking  to 
be  3"  thick  and  secured  to  the  caps  by  trunails.  When  the  platforms 
are  completed,  the  earth  back-filling  to  be  commenced  at  the  wall  or 
river  side,  and  embankment  face  to  be  always  preserved  towards  the 
shore  or  old  bulkhead  line. 

With  a  platform  in  the  rear  of  the  wall,  of  the  extent  proposed,  thus 
supported,  bonded,  and  back-filled,  we  should  feel  confident  of  the 
security  of  the  whole  structure  ;  and  should  there  at  any  time  be  a  show 
of  weakness  on  the  river  face  of  the  concrete,  by  further  abrasions, 
they  will  be  gradual,  giving  ample  notice  of  the  necessity  of  repair, 
without  endangering  general  stability. 

On  the  8th  of  December  last,  we  received  a  communication  from  the 
President  of  the  Department  of  Docks,  enclosing  a  memorandum  pre- 


31 


pared  by  Mr.  G.  S.  Greene,  Jr.,  Engineer-in-Chief  of  the  Department, 
suggestive  of  a  request  for  fuller  expression  of  our  opinion  as  to  the 
"  system  employed  in  said  constructions  ;  "  which  suggestion  was 
approved  by  the  Commissioners. 


Memorandum  for  President  Wales. 

"  Understanding  that  it  is  no  part  of  the  duty  of  the  Board  of  Engi- 
"  neers  at  present  examining  the  bulkhead  wall  to  express  their 
"  opinion  as  to  the  system  or  principle  employed  in  its  construction,  1 
"  beg  leave  to  suggest  that  it  would  be  well  to  request  said  Board  to 
"  report  and  express  definitely  their  opinion  in  regard  to  the  system 
"  employed  ;  because,  though  from  their  report  in  regard  to  present 
"  condition  and  advice  as  to  what  shall  be  done  in  the  future,  their 
"  opinion  as  to  the  system  may  be  inferred,  it  would  be  much  better  for 
"  this  Department  to  have  a  decided  and  definite  expression  of  their 
"  opinion. 

"  In  case  they  report  the  wall  faulty,  this  expression  of  opinion  would 
"  decide  whether  it  is  so  by  reason  of  the  system,  or  of  bad  work  under 
"  a  good  system,  and  it  would  also  prevent  different  persons  making 

different  inferences  from  their  report  in  regard  to  this  point. 

"  Respectfully  submitted, 
(Signed)  "  G.  S.  GREENE,  Jr. 

' '  Engineer-  in-Ch  ief. 

[Jn  Answer.] 

Throughout  our  report  will  be  found  full  details  of  the  defects 
of  the  structures  under  examination,  and  remarks  on  what  we  con- 
sider the  causes  of  such  defects,  and  how  they  might  probably  be 
obviated.  But  we  suppose  Mr.  Greene  intended  his  request  for  our 
opinion  as  to  the  system  of  constructing  concrete  mass  in  situ  beneath 
the  surface  of  water.  We  cannot  condemn  a  system  of  which  many 
successful  examples  are  reported,  with  which  we  are  conversant,  nor, 
under  certain  circumstances  and  necessities,  should  we  hesitate  to 
adopt  it  ;  but  these  do  not  obtain  in  the  construction  of  these  bulk- 
heads ;  and  we  should  recommend  that  all  exterior  faces  here  should  be 
constructed  in  blocks  and  deposited  on  the  pile  foundations  as  hereto- 
fore described  in  our  modification  of  the  present  structures. 


(Signed) 


JOHN  NEWTON, 
Q.  A.  GILLMORE, 
WM.  E.  WORTHEN. 


32 


EXAMINATIONS  OF  THE  CONCRETE  EN  MASSE  OF  THE 
CANAL  STREET  SECTION.  AS  MADE  BY  DIVER 
T.  W.  CON  KLIN.  UNDER  DIRECTION 
OF  JOHN  NEWTON. 

Panel  No.  19.  Partly  under  and  partly  north  of  pier.  Shutter 
removed  to  depth  of  4  feet  6  inches  only  below  offset.  Seam,  2  feet 
below  offset,  running  straight  across  panel,  iy2  inches  wide,  too  soft 
to  furnish  samples.  Probed  with  steel  rod  }(  inch  square,  gave  depths 
of  12  inches,  9  inches,  and  19  inches  at  the  extreme  and  middle  points. 
By  tapping  the  rod  with  a  hammer,  a  depth  of  25  inches  in  the  seam 
was  reached.  A  hard  blow  with  hammer  could  not  be  made  on 
account  of  the  bending  and  springing  of  the  rod.  Drove  in  a  steel 
chisel  everywhere  its  whole  length  of  8  inches  with  great  ease  and 
quickness  by  tapping  with  hammer. 

Samples  from  top  edge  of  seam.  No.  1  from  face  of  wall,  top  of 
drowned  cement  and  soft  bottom,  more  sand  and  better  set.  No.  2, 
face  of  wall,  soft  with  little  sand.  No.  3,  soft  and  harder  set  in  equal 
proportions. 

Samples  from  bottom  edge  of  seam.  No.  4,  separate  layers  of 
cement  and  sand  without  set.  No.  5,  mostly  cement,  little  sand, 
sott.  No.  6,  separate  layers  of  cement  and  sand  without  set.  Sample 
No.  7,  one  foot  below  seam,  hard. 

Panel  No.  12.  South  of  preceding  with  6  panels  between;  under 
pier.  Wall  exposed,  by  removal  of  shutters,  only  to  a  depth  of  3  feet 
below  offset.  Seam,  18  inches  and  24  inches  below  offset,  4  inches 
wide.  Penetrated  by  steel  rod  6  inches,  13^  inches,  and  13  inches  at 
extreme  and  middle  points.  Penetration,  by  tapping  with  hammer. 
17  inches.  Seam  was  soft.  Two  samples  from  face  well  set.  Surface 
of  wall  hard,  and  could  not  get  the  steel  rod  in.  Would  have  to  drill 
it  with  the  chisel. 

Panel  No.  11.  South  of.  and  contiguous  to.  preceding  ;  under  pier. 
Six  feet  of  this  panel  measured  below  offset,  exposed  to  inspection. 
Seam,  2  feet  below  offset  and  4  inches  wide.  Penetrations,  with  steel 
rod,  qy2,  $lA<  ancl  4  inches  at  extreme  and  middle  points.  Hole  in 
north  side  of  panel,  6  inches  in  diameter  and  16  inches  deep.  Pene- 
tration of  rod  by  hammer.  21  inches. 

Sample  from  seam :  cement  and  sand  in  separate  layers  :  setting 
poor.    Sample  from  bottom  of  hole,  very  soft  cement. 

From  face  of  wall.     Sample  :  stone  with  soft  cement  around  it. 


33 


Sample  :  cake  from  around  hole ;  hard  on  outside,  soft  on  inside. 
Sample  :  thin  cake  from  surface,  cement  tolerably  set.  Sample  :  al- 
most pure  cement  and  soft.  Rod  went  in  12  inches.  Sample  :  cement, 
little  sand,  hard  on  surface.  Sample  :  stones  with  soft  cement  around 
them. 

On  this  panel,  whenever  the  hard,  thin,  outer  crust  was  removed, 
the  stones  could  be  taken  out  by  hand. 

Panel  No.  10.  South  of,  and  contiguous  to,  preceding  ;  under  pier. 
Exposed  to  depth  of  9  feet  below  offset.  Seam,  2  feet  below  offset. 
Penetrations  were  made  with  steel  rod  along  two  vertical  lines,  near 
the  north  and  south  sides,  respectively,  of  the  panel. 

North.  South. 

10  inches  at  seam.  1 1  inches  at  seam. 

17    "      4  ft.  6  in.  below  offset.  39    "      4  ft.  6  in.  below  offset. 

39    "      near  bottom.  34    "      near  bottom. 

Sample  from  seam  :  small,  of  drowned  cement.  Samples  from  wall, 
21  inches  above  bottom.  Sample  :  cement,  very-  dark,  tolerably  hard, 
softer  on  inside.    Sample  :  very  dark,  muddy,  not  well  set. 

This  panel  without  hard  outside  skin,  and  the  face  of  wall  can  be 
removed  by  hand.    The  wall  is  rather  harder  above  the  seam. 

Panel  No.  9.  South  of.  and  contiguous  to,  the  preceding ;  under 
pier. 

Panel  exposed  to  depth  of  10  feet  below  offset.  Seam,  2  feet  below 
offset.  Penetrations  of  steel  rod  along  two  vertical  lines  at  the  north 
and  south  sides  of  the  panel. 

North.  South. 

13  inches  at  seam.  13  inches  at  seam. 

19^  "     half-way  down.  24^  "     half-way  down. 

45     "     near  bottom.  61      "     near  bottom. 

Surface  of  wall  soft,  and  can  be  removed  anywhere  by  hand. 

Panel  No.  8.  South  of,  and  contiguous  to,  preceding ;  under  pier. 
Seam,  2  feet  below  offset  at  north,  and  20  inches  below  at  south  end  of 
panel.  At  south  end  the  field  enlarges  into  a  hole,  filled  with  stones 
without  mortar,  2  feet  in  diameter  and  14  inches  deep,  but  not  fully 
explored.  Penetration  of  steel  rod  along  vertical  lines  at  north  and 
south  sides  of  panel. 

North.  South. 

\ol/z  inches  at  seam.  14  inches  at  seam,  in  hole. 

15       "       half-way  down.  38      "       half-way  down. 

71       "      near  bottom.  62      "      near  bottom. 


Sample,  from  seam  :  stones  with  little  mortar,  without  consistence. 


Sample,  half-way  down  :  stones  with  soft  mortar,  having  excess  of 
cement.  Sample,  near  bottom  :  large  sample  of  drowned  out,  soft 
cement  and  muddy.  These  three  samples  taken  along  north  vertical 
line. 

From  south  vertical  line.  Sample,  from  hole  :  stones  without 
mortar.  Sample,  half-way  down  :  stone  with  mere  skin  of  drowned 
cement.  Sample,  from  near  bottom  :  of  cement  and  sand,  unequally 
distributed,  easily  crushed  in  fingers  ;  mud  on  bottom  of  sample. 

The  outer  surface  of  this  panel  is  soft,  and  can  be  easily  removed  by 
hand  everywhere. 

Pa?iel  No.  j.  South  of,  and  contiguous  to,  the  preceding.  Exposed 
to  depth  of  10  feet  below  offset.  Penetrations  of  steel  rod  along  north 
and  south  vertical  lines.    Seam,  20  inches  below  offset. 


Samples  along  north  vertical  line.  Sample,, from  seam  :  one  stone, 
on  the  back,  soft  drowned  cement.  Sample,  half-way  down  :  cement 
with  little  or  no  sand,  soft,  except  a  thin  skin  on  outside  1-20  inch 
thick,  which  was  harder.  Sample,  from  a  small  section  of  smooth 
surface,  2  feet  above  bottom  :  outside  hard,  inside  soft.  At  the 
bottom,  the  diver  reported  concrete  soft  as  in  preceding  panel. 

Samples  from  south  vertical  line.  Sample,  from  just  below  seam  : 
a  little  soft  mortar  brought  up  on  the  chisel,  surface  is  harder ;  when 
penetrated,  the  diver  reports  all  soft.  Sample,  about  midway  down, 
from  a  hole  :  thin,  hard  film  on  outside,  the  rest  nearly  all  cement, 
easily  crushed  in  fingers.  Another  sample  from  hole,  tolerably  well 
set  for  one-and-a-half  inches  from  surface  ;  the  interior  soft.  This 
hole  was  just  long  enough  to  get  in  the  hand,  but  expanded  on  the 
interior;  it  was  17  inches  deep.  Sample,  from  bottom  :  nearly  pure 
cement  and  soft. 

This  panel  is  like  the  preceding,  except  that  the  hard,  thin,  exterior 
crust  has  not  been  so  much  scaled  off. 

Panel  No.  3.  South  of,  and  with  an  interval  of.  three  panels 
between  it  and  the  preceding.  This  panel  south  of  pier.  Exposed  to 
depth  of  11  feet  below  offset.  Penetrations  of  steel  rod  along  vertical 
line  near  middle  of  panel. 


North. 


South . 


8  inches  at  seam. 
29      •'     half-way  down. 
39     "     near  bottom. 


9  inches  at  seam. 
24      "     half-way  down. 
26^  "     near  bottom. 


33 


1 2 


6  inches,  one  foot  from  top. 
2  "  four  feet  from  top. 
,3      "      eight  feet  from  top. 


Sample,  one  foot  from  top  :  very  soft,  drowned  cement.  Sample, 


35 


four  feet  from  top  :  stone,  with  soft  cement  on  back,  and  piece  of 
mortar,  soft  on  back,  all  easily  crunched  in  fingers. 

Sample,  about  2  feet  above  bottom  :  stone  without  mortar ;  also  a 
separate  piece  of  mortar,  nearly  all  cement,  and  very  soft  indeed. 

Wherever  the  thin,  outer  scale  was  removed,  the  interior  proved  to 
be  soft ;  if  anything-,  more  so  than  in  the  preceding  cases. 

Two  Panels,  Nos.  27  and  28.  North  of  wharf,  and  separated  from 
Panel  No.  19  by  seven  panels.  Exposed  to  depth  of  6  feet  below 
offset.  Next  to  north  pile,  surface  much  broken  and  can  be  easily 
removed.  Near  north  pile  and  18  inches  below  offset  the  steel  rod 
went  in  9  inches  ;  could  not  penetrate  on  account  of  stones,  except  at 
this  point,  along  that  vertical  line.  Sample,  stones  from  face  of  wall, 
taken  by  hand  :  mortar  almost  pure  sand.  Sample  :  stone  with  slight 
trace  of  drowned  cement  on  back. 

Along  the  middle  vertical  line  the  rod  penetrated  9  inches,  about  one 
foot  below  offset,  and  nowhere  else  along  this  line,  on  account  ol 
stones. 

Along  south  vertical  line  the  rod  penetrated  8  inches,  about  3  feet 
below  offset,  and  nowhere  else,  on  account  of  stones,  along  this  line. 

Sample  :  stones  with  slight  traces  of  drowned  soft  cement.  Sample  : 
four  stones  with  slight  trace  of  mortar.  Sample  :  cement  tolerably 
set  on  outside,  soft  on  inside.  This  sample  was  got  out  by  a  chisel, 
which  made  a  hole  10  inches  deep,  the  concrete  being  softer  as  it 
progressed. 

The  diver  reported  that  he  could  pick  the  face  all  to  pieces  with  his 
hands.  Nearly  all  the  specimens  obtained  from  the  panels  examined 
on  the  26th  and  27th  of  November  were  small,  because,  according  to 
the  diver's  report,  the  mortar  was  so  soft  or  badly  set  that  it  was  impos- 
sible to  get  out  larger  pieces. 

[End  of  first  examination  of  face  of  wall,  Canal  Street  section.] 


End  of  Wall. 

At  west  side  of  cross  section,  9  feet  to  the  top  of  pile.  Steel 
rod,  along  vertical  line,  about  4  feet  from  face  of  the  wall, 
would  not  go  in  over  3  inches  because  of  stones  ;  no  seam  found  ; 
surface  rough.  No  shutters  had  been  placed,  this  end  having  been 
supported  by  piles  driven  close  together. 

Samples  from  surface,  on  vertical  line,  about  4  feet  east  of  face  of 
wall,  and  one  foot  below  level  of  offset  :  many  stones,  without  adhering 
mortar ;  one  with  mortar  having  large  excess  of  sand  and  tolerably 
set.  Sample,  along  same  line,  and  about  half-way  down  :  many  stones 


3C> 


without  mortar,  also  two  clusters  cemented  with  mortar  having  large 
excess  of  sand  and  tolerably  set.  Sample,  along  same  line,  and  near 
bottom  :  one  cluster  cemented,  excess  of  sand. 

Near  top  of  wall,  and  on  same  vertical  line,  a  hole  was  dug  with 
chisel,  aided  by  hammer,  to  a  depth  of  14  inches.  Sample  :  two 
clusters  cemented  together,  from  outside  of  hole,  large  excess  of  sand. 
Sample,  from  bottom  of  hole  :  large  number  of  stones,  great  deficiency 
of  mortar,  large  excess  of  sand  generally ;  but  one  specimen  showed 
any  cohesive  strength.  Some  specimens  also  had  traces  ot  soft 
drowned-out  cement.  In  this  sample  there  was  no  cementing  matter 
shown  upon  the  large  proportion  of  surfaces. 

Samples  from  middle  hole  on  same  vertical  line,  worked  16  inches 
deep  by  chisel  and  occasional  use  of  hammer  :  mortar  on  most  of  the 
stones,  but  only  in  two  or  three  instances  all  around  the  stones.  In 
other  cases  one  or  more  of  the  surfaces  of  the  stones  showed  no 
adhering  mortar.  The  mortar,  when  it  adhered,  was  generally  set, 
showing  excess  of  sand,  but  in  most  instances  there  was  a  deposit  on 
the  surface  of  the  mortar  of  a  soft  material,  like  drowned  cement. 
Sample,  on  the  whole,  one  of  the  best  obtained. 

Bottom  hole,  in  same  vertical  line,  dug  24  inches  deep.  Two  stones, 
nearly  enveloped  in  mortar,  weak  from  excess  of  sand.  Portion  of  the 
sample  from  the  interior  of  the  hole  showed  stones  imperfectly 
imbedded  in  mortar  containing  a  large  excess  of  sand,  with  seams  of 
soft,  drowned  cement  interspersed. 

The  bottom  hole  caved  in,  forming  an  opening,  up  and  down,  of 
3  feet  by  1  foot  wide  ;  a  large  mass  of  material  fell  in. 

In  all  these  holes  the  stones  were  easily  removed,  and  there  were  no 
signs  of  having  to  stop,  as  far  as  they  were  dug. 

On  eastern  half  of  cross  section,  a  large  caving  in  was  found, 
extending  horizontally  for  the  half-width  of  cross  section,  vertically 
about  \Yz  feet,  and  was  19  inches  deep. 

This  caving  was  caused,  as  I  am  informed,  by  the  shocks  of  the  pile- 
driver  in  extending  the  piling  southward,  after  the  piles  sustaining  the 
end  of  the  wall  had  been  removed. 

Pafiel  No.  7.    Just  south  of  south  line  of  pier  prolonged. 

On  south  half  of  panel,  4  feet  from  top,  a  seam  4  feet  long,  2  inches 
wide,  and  18  inches  deep.  Sample  from  surface,  6  feet  from  top  : 
stones  with  mortar  adhering  in  two-thirds  of  the  instances  ;  mortar 
with  large  excess  of  sand.  Sample,  from  bottom  of  a  hole,  19  inches 
deep  :  stones  showing  adhesion  of  mortar,  some  of  it  good,  in  others 
excess  of  sand  ;  relatively  a  fair  sample  of  concrete  ;  a  little  soft 
drowned  cement. 

On  north  half  of  panel,  for  3  feet  down,  surface  of  wall  was  smooth, 
and  could  not  enter  the  rod.    Surface  can  be  easily  removed  by  using 


37 


the  rod.  Below  this  the  surface  is  gone  in  many  places.  Sample  of 
stones  from  surface  showed  clearer  indications  of  being  imbedded  in 
mortar,  and  of  well  set,  adhering  mortar,  than  usual. 

Panel  No.  ri.  Under  pier,  re-examined.  Could  not  obtain  samples 
from  top  and  middle  seams,  because  too  soft.  Seams  very  narrow, 
about  i  inch  in  width. 

Panel  No.  10.  Under  pier.  South  of,  and  contiguous  to,  pre- 
ceding. .  Re-examined. 

Sample,  from  bottom  seam  :  cement  soft,  in  layers  with  mud  or  dirt. 
Sample,  from  middle  seam  :  cement,  most  of  it  soft  mush.  Sample, 
from  top  seam  :  cement  soft,  not  quite  as  much  so  as  sample  from 
middle  seam.  Top  seam,  3  inches  wide.  Sample  of  mortar,  from  top 
edge  of  this  seam  :  cement  with  some  sand,  very  tough. 

Panel  No.  9.  Under  pier.  South  of,  and  contiguous  to,  preceding. 
Re-examined. 

Penetration  of  steel  rod,  in  seams,  about  the  middle  of  the  panel  : 

Bottom  seam,  about  9  inches  wide  ;  penetration,  42  inches. 
Middle     "        "     4  .  "  26 

Top         "        "  "        "  "  14  " 

Top         "      second  trial,  "  8 

Between  bottom  and  middle  seams,  in  middle  of  panel,  could  not 
enter  the  rod.    Surface  full  of  stones.    A  hard,  firm  place. 

Between  middle  and  top  seam,  near  middle  of  panel  could  not  get 
in  the  rod. 

Sample  from  bottom  seam  ;  cement  soft,  in  layers  with  mud  and  dirt. 
Face  of  bottom  seam  in  places  has  fallen  out  to  depth  of  5  or  6 
inches.  Place  where  sample  was  taken  from,  12  inches  square.  In 
places  as  much  as  14  or  15  inches  wide  without  stone. 

Middle  seam  too  soft  to  get  sample  from.  Sample  of  stones  from 
upper  and  lower  edges  of  seam,  show  little  good  mortar — generally 
sand  or  drowned  cement. 

Sample  from  top  seam,  taken  from  a  place  1  foot  high  :  soft  cement  ; 
behind  the  cement  were  stones  easily  removed  by  hand  ;  most  of  this 
sample  very  soft. 

Panel  No.  8.  South  of,  and  contiguous  to,  preceding.  Under  pier. 
Re-examined. 

Penetrations  of  steel  rod  in  the  seams,  about  the  middle  of  the  panel  : 

Bottom  seam,  12  in.  wide  ;  penetration,  23  in.  and  38  in. 
Middle  seam,  4  to  6  in.  "  "  35  in.  and  38  in. 

Top  seam,  "  "  10  in. 


In  middle  of  panel,  rod  would  not  enter  between  top  and  middle 


38 


seams,  on  account  of  stones.  Stone  with  cement  adhering  to  it  rather 
hard. 

In  middle  of  panel,  rod  would  not  enter  between  middle  and  bottom 
seams,  on  account  of  stones.  Sample  stones  tolerably  imbedded  in 
mortar ;  excess  of  cement,  and  tolerably  set.  Stones  were  easily 
removed  by  hand.  Sample  from  bottom  seam  from  a  place  12  inches 
square  and  10  inches  deep  :  cement  in  layers,  no  stone  ;  dirty,  finer 
portions  escaped  in  bringing  up,  not  set  or  but  slightly. 

Sample  from  middle  seam,  from  a  space  6  in.  wide,  12  in.  high,  and 
6  in.  deep  :  Two  stones  ;  cement  in  layers  ;  not  as  dirty  as  in  bottom 
seam  ;  not  set,  or  but  slightly. 

Pa?tel  No.  7.  South  of  and  contiguous  to  the  preceding — about  on 
a  line  with  south  side  of  pier.  Re-examined. 

Bottom  seam,  12  inches  wide.  Iron  rod  penetrated  35  inches,  all  the 
way  across. 

Middle  seam  about  6  inches  wide  ;  maximum  penetration,  38  inches, 
minimum,  32  inches.  Top  seam,  penetrations  \o]/2  inches,  15  inches, 
and  16  inches. 

Thin  crust  from  space  between  top  and  middle  seams.  Cement  and 
sand  in  layers,  rather  hard.    Iron  rod  went  in  1 1  inches. 

Between  middle  and  bottom  seams,  rod  would  not  penetrate  on 
account  of  stones.  Sample  stones  with  mortar  adhering,  having  excess 
of  sand,  with  thin  seams  of  drowned  cement  interspersed. 

The  samples  obtained  from  the  seams,  during  the  re-examination  on 
the  6th  and  7th  of  December,  were  transferred  to  a  warm  room,  and 
kept  wrapped  in  paper  to  prevent  drying.  After  remaining  thus  for  8 
and  9  days,  the  papers  were  opened,  the  cement  was  found  moist ;  but 
in  every  case  without  the  least  appearance  of  set.  The  samples 
resembled  so  much  mud. 

The  samples  were  then  allowed  to  dry,  and  except  when  dirt  had 
mingled,  they  were  generally  very  light  colored,  almost  white ;  sepa- 
rating in  thin  layers  which  marked  successive  depositions  ;  of  low 
specific  gravity  apparently,  the  cakes  being  so  light  as  to  float  until 
they  absorbed  water,  which  was  quickly  accomplished. 

The  important  facts  to  be  gathered  from  the  foregoing  notes  of 
examination,  are  : 

1.  Deficiency  in  hardness  and  set  of  the  concrete  to  the  extent  to 
which  the  examinations  progressed.  The  surface  of  the  concrete,  in 
nearly  every  case,  was  easily  removed  by  hand. 

Holes  were  easily  and  expeditiously  excavated  into  the  mass,  to 
depths  varying  from  14  to  24  inches,  and  the  concrete  did  not  become 
harder  as  the  penetration  progressed. 

2.  The  inferior  condition  of  the  mortar,  which,  in  the  large  majority 
of  instances,  was  classed  as  drowned  cement,  soft;  cement  with  sand 


39 


in  separate  layers,  with  little  or  no  set  ;  sand  with  a  trace  of  cement, 
easily  crumbled  in  the  fingers,  etc.  ;  terms  which  indicate  that  the 
concrete  had  been  subjected  effectually  to  the  water-sifting  process,  by 
which  the  constituent  parts  of  the  mortar  had  become  separated  from 
each  other,  to  the  injury  or  destruction  of  cohesive  strength. 

3.  The  presence  of  extensive  seams  along  the  face  of  the  concrete 
mass,  principally  encountered  under  the  pier  of  the  Pacific  Mail  Steam- 
ship Company.  Wherever  the  shutters  had  been  removed  to  depths 
of  3,  6  and  10  feet  respectively  from  the  offset,  one,  two,  and  three 
seams  were  found,  which  indicates  that  the  three  seams  existed  for 
the  whole  length  of  the  wall  under  the  pier. 

The  seams  undoubtedly  correspond  to  the  upper  surfaces  of 
successive  layers  of  concrete,  and  although  probed  from  the  outside 
with  a  steel  rod,  as  effectually  as  would  be  done  by  a  diver,  it  is  by  no 
means  certain  that  the  full  depths  have  been  obtained,  because  of  the 
probable  presence  of  stones  here  and  there,  and  of  the  irregular  and 
waving  form  of  the  beds  upon  which  the  seams  lie. 

The  lowest  seam,  corresponding  to  the  top  of  the  first  layer  of  con- 
crete was,  measured  on  the  outside,  of  a  thickness  from  9  to  about  18 
inches.  The  average  penetration  was  44  inches,  the  least  being  27,- 
and  the  greatest  71  inches. 

The  middle  seam,  corresponding  to  the  second  layer,  measured  from 
1  to  9  inches  in  depth  on  the  surface  of  the  wall.  The  average  pene- 
tration was  28  inches  ;  the  least  being  1  5.  and  the  greatest  39  inches. 

The  upper  seam,  corresponding  to  the  third  layer,  measured  on  the 
surface  from  1  to  4  inches  in  depth.  The  average  penetration  was  12 
inches  ;  the  least  being  4,  and  the  greatest  25  inches. 

Samples  of  these  seams,  from  excavations  made  into  the  wall,  to  a 
depth  of  12  inches,  were  tested  under  favorable  conditions  for  a  period 
of  nine  days,  without  the  slightest  appearance  of  set. 

From  the  middle  and  top  seams  much  of  the  material  was  a  mush  ; 
while  from  the  lowest  seam,  the  material,  in  its  wet  state,  presented  the 
appearance  of  having  been  compressed.  On  drying  them,  however, 
all  the  lump  samples  turned  out  the  same — that  is,  very  light  and 
porous. 

When  the  concrete  was  green,  its  weight  undoubtedly  compressed 
the  seams  ;  but  as  the  layers  began  to  consolidate  and  become  self- 
supporting,  the  materials  of  the  seams  relieved  in  part  of  pressure, 
yielded  more  readily  to  the  dissolving  and  washing  power  of  the  water, 
and  have  become  very  porous  or  mushy.  For  a  certain  distance  in 
from  the  face,  the  seams,  therefore,  give  no  support  to  the  layers  of 
concrete. 

I  have  been  informed  that  the  intention  of  the  constructor  was  to 
have  had  the  deposits  upon  the  top  of  each  layer  cleaned  off  before 


40 


the  next  layer  should  he  placed.  His  instructions  were  but  partially 
executed,  it  is  true,  but  sufficiently  so  to  prevent  the  seams  being  found 
continuous  through  the  width  of  the  wall.  For  there  is  no  reason, 
other  than  that,  to  account  for  the  non-appearance  of  a  feature  which, 
in  the  general  case,  should  have  been  uniform  for  the  same  layer  of 
concrete. 

This  consideration  opens  to  view  the  large  extent  of  these  seamy 
deposits,  of  which  only  a  fraction  have  been  Left  for  our  inspection,  but 
sufficient  to  prove  that  the  waste  of  cement  by  the  water-sifting 
process  was  great,  and  the  injury  done  to  the  concrete  in  proportion. 

4-  Another  fact,  worthy  of  record,  was  the  formation  of  a  very  thin, 
hard  scale,  more  or  less  extensive,  upon  the  outer  surface  of  the  mass 
concrete.  This  indicates  a  conservative,  rather  than  destructive, 
influence  of  the  dock  water. 

However,  as  the  Commissioners  have  it  in  their  power  to  discharge 
the  sewer  water  into  the  current  at  the  end  of  the  piers,  the  question 
ol  its  effect  upon  the  bulkhead  wall  loses  much,  if  not  all,  of  its  prac- 
tical importance.  Experiments  in  the  Department  have  been  instituted 
upon  the  effects  of  the  sewer  water  upon  Portland  cement  concrete, 
already  with  definite  results  ;  and  it  would  seem  best  to  leave  the 
matter  there. 

Mr.  B.  Latham  (Exc.  minutes  of  the  Proceedings  of  the  Institution 
of  Civil  Engineers,  Vol.  XXXII.  Session  1870-71,  Part  II.)  states: 
"  During  the  last  two  years  he  had  found  that  sewers  which  had  been 
"  constructed  for  about  seventeen  or  eighteen  years,  the  brickwork  of 
"  which  was  set  in  various  kinds  of  lime  and  cement,  and  in  some 
"  cases  in  a  mixture  of  both,  were  failing,  and  many  yards  of  such 
"  sewers  had  fallen  in."  This  was  due  to  the  disappearance  from  the 
joints  of  every  particle  of  cement  or  lime.  He  also  states  that  Portland 
cement  was  the  best  material  for  resisting  the  chemical  action  of  sewage. 

It  will  be  observed  above  that  it  required  seventeen  or  eighteen  years 
to  produce  the  effect,  under  exposure  to  the  concentrated  effect  of  the 
chemical  action,  in  the  sewer  itself. 

The  Portland  cement  used  was  of  good  quality,  slow  setting,  and 
weighed  about  112  lbs.  to  the  struck  bushel.  The  constituents  of  this 
cement  are  of  very  different  specific  gravities,  and  the  particles,  which 
are  of  several  degrees  of  fineness,  vary  considerably  in  weight. 

The  paste  of  such  cement  is  not  unctuous,  like  that  of  Rosendale 
cement  and  hydraulic  limes,  and  is  consequently  destitute  of  the 
power,  possessed  by  these  in  a  green  state,  to  hold  the  mortar  well 
together  when  exposed  to  the  wash  consequent,  generally,  upon 
lowering  in  water  and  depositing.  This,  which  was  indeed  a  prior 
conclusion,  has  been  proved  experimentally. 

In  experiments  made  with  the  same  bucket  that  was  used  for  the 


+1 


actual  construction  of  the  mass  concrete,  and  under  precisely  the  same 
conditions,  it  was  noticed  repeatedly  that,  before  complete  immersion, 
the  water  had  penetrated  through  the  load  of  concrete  from  the  bottom 
to  the  top,  and  was  flowing  through  in  a  continuous  stream.  At  the 
moment  of  immersion  the  surface  water  tumbled  into  the  bucket  with 
a  considerable  force — for  the  bucket  was  not  full  and  had  no  top — and 
added  to  the  wash. 

The  bucket  is  of  wedge  shape,  lowered  into  the  water  with  the  edge 
downwards,  and  has  its  discharging  gate  on  the  side.  The  consequence 
is  that,  instead  of  depositing  its  load  in  mass  by  one  operation,  the 
concrete  is  compelled  to  slide  out  in  successive  portions  through  the 
water  and  undergo  the  sifting  process. 

The  formation  level  is  a  layer  of  4-inch  rubble,  packed  or  placed 
between  the  heads  of  the  foundation  piles,  which  last  projects  variously, 
sometimes  several  feet,  above  the  rubble.  The  bucket,  stopped  in  its 
descent  by  the  heads  of  the  piles,  must  discharge  through  several 
additional  feet  of  fall  before  its  contents  can  reach  their  bed. 

Under  such  circumstances  the  sand  and  heavier  portions  of  the 
cement  fall  to  the  bottom  and  penetrate  into  the  rubble  below,  while 
the  lighter  portions  float  and  form,  by  subsequent  deposit,  the  lowest 
seam,  which  was  uniformly  found  to  be  the  thickest  of  the  three. 

The  concrete  between  the  pile-heads,  deprived  thus  of  mortar,  is 
generally  a  mere  mass  of  rubble,  not  cemented  at  all,  or  but  imperfectly. 

The  pile-heads  have  not  been  sawed  off,  except,  perhaps,  those  of 
the  front  and  back  rows.  In  addition  to  sticking  up  irregularly,  a 
number  are  broomed,  or  split,  and,  therefore,  incapable  of  sustaining 
a  full  load.  It  appears  to  have  been  the  idea  that  the  concrete  packed 
between  them  would  grasp  and  bind  the  heads,  as  by  a  ring,  and  so 
compensate  for  their  weakness.  But  when  the  rubble  settles,  as  it 
must,  the  crumbling  concrete  between  the  pile-heads  will  fall  too,  and 
leave  these  without  the  expected  support. 

The  lower,  or  foundation,  layer  of  concrete  is  the  worst  of  the  three 
or  four  layers,  because  the  concrete  has  to  fall  through  a  greater  depth 
after  discharge  from  the  bucket,  and  the  heavier  parts  of  the  mortar 
are  lost  in  the  interstices  of  the  rubble.  It  is  also  clear  that  the  pile- 
heads  should  have  been  cut  to  a  level,  and  an  impervious  bed  or  plat- 
form provided  to  receive  the  first  layer. 

From  the  mode  of  depositing  the  concrete,  as  likewise  from  the 
peculiarities  of  this  slow-setting  cement,  a  considerable  wash  has  also 
taken  place  in  the  layers  above,  although  not  as  much  as  in  the 
lowest  one. 

Owing  to  the  want  of  unctuosity  of  the  cement  and  its  slow  setting, 
the  disintegration  of  the  mortar  continues  some  time  after  deposit,  and 
those  portions,  as  the  sides  of  the  wall  exposed  to  the  water,  show  this 


42 


action  more  than  the  interior  mass,  which  has  been  better  protected. 
It  is  also  evident  that  the  mode  adopted  of  depositing  the  concrete  in 
long  successive  layers  was  injurious,  because  of  the  large  surfaces 
unnecessarily  exposed  to  the  action  of  the  water. 

It  would  have  given  better  results  had  the  full  height  of  the  mass 
concrete  been  deposited  in  sections  of  limited  length,  such  as  to  have 
insured  their  completion  by  a  continuous  operation. 

It  is  not  intended  to  assert  that  there  is  no  concrete  of  fair  quality 
contained  in  this  wall ;  but,  from  the  causes  mentioned,  the  results  are 
so  uncertain  that  serious  defects  have  appeared  in  places  where  the 
wall  was  required  to  be  of  unimpaired  strength.  As  a  monolith  it  is 
imperfect,  if  not  essentially  a  failure  ;  and  besides  the  defects  already 
cited,  attention  should  be  called  to  the  fact  that  the  front  row  of  piles 
intended  to  have  good  bearing,  particularly  against  the  thrust  of  the 
earth  backing,  can  give  no  support  to  the  wall,  because  the  angle  or 
toe  of  the  wall,  against  which  the  piles  abut,  has  fallen  away,  or  is  too 
weak  to  answer  the  purpose. 

At  one  period  Portland  cement  was  used  with  much  misgiving, 
because  of  the  ignorance  and  selfishness  of  manufacturers,  and  the 
want  of  systematic  experiments  calculated  to  explore  the  subject  fully 
or  to  classify  the  properties  of  the  several  varieties.  The  lengthened 
course  of  experiments  of  Mr.  fohn  Grant  were  conclusive  in  their 
effects  to  remove  prejudice  and  to  demonstrate  the  excellence  of  the 
heavier  and  slow-setting  brands. 

Mr.  Henrv  Reid  states,  in  his  work  on  the  manufacture  of  Portland 
cement,  that  "  much  of  the  clamor  against  heavy  cement  is  caused 
"  by  its  slowness  in  setting,  and  doubtless  great  waste  and  loss  is 
"  occasioned  by  many  using  this  quality  of  cement  for  purposes  to 
"  which  it  is  unsuited."  (Edition  of  1868).  But  since  that  period  the 
thorough  endorsement  of  this  quality  by  experiments  and  actual  con- 
struction, has  rather  changed  the  risk  to  the  other  side,  and  induced 
waste  and  loss  by  its  application  to  purpose  for  which  it  is  not  suited. 

The  instances  given  of  the  application  of  Portland  cement  in 
hydraulic  constructions  are  often  vague  and  inconsequent  in  the 
details. 

One  instance  is  taken  from  the  work  just  referred  to  of  the  con- 
struction of  the  foundations,  inside  of  cylinders,  of  a  bridge  across  the 
Thames,  at  Windsor.  The  cylinders  were  sunk  through  the  gravel 
without  pumping,  and,  of  course,  were  full  of  water.  Through  that 
water  the  concrete  was  passed,  and  it  set  well  and  hard  in  eight  or  ten 
days.  The  proportions  were  one  of  cement  to  nine  of  ballast,  increased 
afterwards  to  one  to  six.  On  pumping  out  they  tested  the  concrete  by 
drilling  nearly  three  feet,  and  no  amount  of  drilling,  consistent  with 
reason,  could  make  any  further  impression.    They  were  so  encouraged 


43 


by  this  essay  that  they  applied  the  same  process  in  cylinders,  through 
depths  of  water  from  50  to  70  feet. 

At  first  sight  all  this  sounds  well,  but  when  the  question  comes  how, 
by  penetrating  three  feet  into  the  top  surface  of  the  concrete,  it  is 
possible  to  certify  concerning  the  quality  of  the  concrete  at  greater 
depths,  the  fallacy  of  the  reasoning  becomes  apparent.  Had  such 
mode  of  investigation  been  relied  upon,  we  should  probably  have  found 
no  defect  worth  mentioning  in  the  Canal  or  King  Streets  sections.  If 
the  foundation  upon  which  the  cylinders  rested  was  gravel,  an  inves- 
tigation there  would  show  that  the  bottom  courses  had  lost  their 
cementing  portions,  which  had  fallen  into  the  gravel.  It  made  very 
little  difference,  in  fact,  to  the  security  of  the  pier,  whether  the  con- 
crete was  good  or  bad  at  all  depths,  because  it  was  confined  in  cylin- 
ders ;  but  the  inference,  that  the  concrete  was  good  because  the  piers 
stand,  is  too  gratuitous  to  need  refuting.  The  effect  of  such  loose 
modes  of  presenting  a  subject,  is  simply  to  mislead  engineers,  who  are 
not  experts  in  concretes,  by  the  sanction  of  high  authorities,  into  the 
commission  of  grave  errors.  Mr.  Kinipple,  on  the  other  hand,  quoting 
from  the  same  book,  states  that  he  had  ascertained  that  in  only  one 
inch  of  quiet  water,  concrete  of  Portland  cement,  made  in  the  propor- 
tions of  one  to  three,  was  endangered  by  the  working  out  of  the  silicate, 
or  the  best  of  the  cement,  from  the  ballast ;  and  he  furnishes  an  instance 
in  point  from  his  own  experience.  He  says  further,  that,  to  avoid  this 
for  the  future,  he  had  resolved  that  all  Portland  cement  concrete 
should  be  mixed  on  the  surface  and  allowed  to  set  for  several  hours, 
the  length  of  time  for  setting  to  be  in  proportion  to  the  quantity  of  the 
cement  used  ;  and,  when  set,  to  be  used  in  a  crumbled  condition.  By 
experiments  he  found  that  he  was  able  to  retain  nearly  the  whole  of 
the  cement  without  any  loss  as  to  strength. 

The  two  examples  cited  show  conspicuously  the  differences  of  state- 
ment between  an  engineer  who  knew  something  of  the  subject  and 
was  possessed  of  a  logical  mind,  and  another  who  did  not  enjoy  such 
advantages. 

The  practice  of  the  Imperial  Austrian  engineers  and  of  the  Italians, 
in  the  use  of  concrete  made  with  puzzolana  and  fat  lime,  is  worthy  of 
mention,  as  it  proceeds  on  the  principle  laid  down  by  Mr.  Kinipple.  The 
mixture  is  made  two  or  three  days  before  being  deposited  in  the  water, 
for  fear,  if  used  in  a  green  state,  the  lime  would  be  separated  by  the 
water  from  the  other  ingredients.  After  the  interval  cited,  the  mass  is 
shoveled  or  dumped  into  the  water  without  further  precaution,  and 
makes  excellent  concrete  because  there  is  no  separation  of  the  con- 
stituents of  the  mortar. 

We  have  seen  that  Rosendale  cement  and  hydraulic  limes  which 
possess  unctuous  properties,  can  be  relied  upon  to  hold  together  in 


44 


water  until  setting  takes  place,  and  Mr.  Kinipple  recommends  for  Port- 
land cement  of  the  heavier  varieties,  which  do  not  possess  that  property, 
to  allow  a  partial  setting  before  deposit  in  water.  This  would  be 
worthy  of  trial  by  the  Commissioners  in  a  series  of  experiments  calcu- 
lated to  test  it  severely. 

The  misfortune  of  the  mass  concrete,  deposited  at  Canal  and  King 
Streets,  has  been,  that  it  was  open  to  rigid  investigation  and  test ;  while 
the  concrete  locked  up  in  cylinders  at  a  depth  of  70  feet,  of  which  such 
a  vague  and  flourishing  statement  has  been  published,  is,  fortunately 
for  the  eminent  engineers  concerned,  put  away  beyond  the  reach  of 
an  investigating  committee. 

For  the  rest,  if  the  walls  at  King  and  Canal  Streets  be  regarded 
as  simple  experiments,  their  value  in  saving  future  loss  by  forcing 
builders  back  to  the  true  principles  of  using  concrete,  will  more  than 
compensate,  even  to  the  Department,  for  the  loss  and  delay  incurred. 

The  defect  of  weakness  found  in  the  toe  of  the  wall,  by  which  the 
front  row  of  piles  have  lost  their  bearing,  and  transferred  that  bearing 
to  the  second  row,  has  in  reality  diminished  the  stability  of  the  wall 
one  quarter. 

An  error,  in  my  opinion,  was  committed  in  driving  close  together  the 
front  and  back  row  of  piles.  By  this  means  the  wall  is  really  prolonged 
to  the  bottom  of  the  piles,  without  increasing  its  weight  or  resistance 
to  overthrow'  one  particle  ;  while,  on  the  other,  the  rows  of  piles  and  the 
walls  supported  on  them,  have  to  endure  the  preponderance  of  the 
thrust  of  the  filling  behind  communicated  through  the  mud  now  in 
place. 

This  thrust  is  as  easily  calculated  as  any  other  against  a  dock  wall, 
and  by  the  same  rules  ;  and,  it  seems  to  met,  should  be  me  by  as  definite 
a  contrivance  to  resist  the  pressure,  as  would  be  done  in  ordinary  cases. 

The  system  of  throwing  in  rip-rap  stone  in  front  of  the  wall  and  of 
driving  piles  behind  the  wall,  to  resist  and  break  up  the  thrusts,  seems 
to  me  very  uncertain  and  unreliable ;  since  these  cannot  be  based 
upon  definite  calculation,  and  it  is  impossible  to  tell  whether  sufficient 
has  been  done  or  not.  The  yielding  of  the  wall,  which  it  should  have 
been  the  purpose  to  prevent,  would  seem  to  be  the  only  monitor  in 
such  cases. 

These  matters  will  be  made  the  subject  of  remark  in  joint  report, 
and  nothing  more  need  be  said  in  this  place. 

Respectfully  submitted, 

JOHN  NEWTON. 


45 


King  Street  Quay  Wall. 

Notes  of  an  inspection  made  by  Q.  A.  Gilbnore,  with  Marine  Diver 
John  Burt,  between  October  13th  and  October  26,  1875. 

The  spaces  between  the  square  caisson  piles,  which  stood  8  feet  apart 
between  centres,  are  termed  panels  in  the  following  notes.  They  are 
numbered  from  north  to  south,  in  both  front  and  rear.  Where  the 
shutters,  or  plank-panels,  between  the  piles  had  not  been  removed,  a 
note  to  that  effect  is  inserted,  as  no  inspection  could  be  made  in  such 
cases.  A  plan,  cross  section,  and  elevation  of  the  wall  and  foundation 
is  shown  on  Plate        accompanying  the  joint  report. 

In  the  first,  second  and  third  panels  (front),  (the  shutters  are  still  in ). 
Not  examined. 

Fourth  panel  (front),  concrete  offset  at  base  of  wall  mostly  gone, 
and  can  be  easily  picked  off  with  the  hand  where  it  remains. 

Some  of  the  4-inch  rubble-stones  were  brought  up  from  under  the 
concrete  about  1  foot  inside  the  face  of  same.  They  were  easily  taken 
out  by  hand.  Rubble  at  this  point  sustains  none  of  the  weight  of  the 
wall. 

A  pile  under  the  wall  was  felt  where  the  rubble  had  settled  away 
from  concrete.  It  is  not  certain  whether  this  pile  belonged  to  first  or 
second  row  from  face  of  wall,  probably  the  first. 

Nearly  half  a  bucketful  of  concrete  stone  was  picked  off  and  brought 
up  from  face  of  wall,  5  to  6  feet  above  the  bottom. 

Face  of  concrete,  over  entire  panel,  rough  and  uneven,  only  a  very 
small  portion  of  it  being  the  original  face. 

Depressions  in  face,  5  inches,  6  inches,  7  inches  and  more  in  depth, 
and  easily  enlarged  with  the  fingers. 

Offset  measurements,  horizontally  from  the  north  panel  pile,  showed 
that  at  the  bottom  the  concrete  had  fallen  away  from  face  to  a  depth  of 
19  inches,  and  half-way  (or  6  feet)  up,  to  a  depth  of  13  inches.  (See 
Fig.  1,  Plate  I.) 

Fifth  panel  (front),  concrete  offset  mostly  gone  as  in  fourth  panel, 
but  not  quite  so  badly. 

Of  the  original  face  of  concrete,  only  about  4  or  5  superficial  feet 
remain,  the  rest  having  crumbled  off,  but  apparently  the  loss  is  not  so 
great  in  depth  as  in  fourth  panel.  Along  the  toe  of  the  wall,  the  con- 
crete stone  from  the  face  above  is  piled  a  foot  high. 

Horizontal  offsets  show  that,  at  the  north  panel  pile,  the  concrete  has 


46 


fallen  off  the  face  of  wall  to  a  depth  of  1 1  inches,  making  a  cavity  about 
5  inches  deep  under  lower  granite  block,  6*4  inches  deep  at  \]4.  feet 
below  granite,  and  iyv2  inches  deep  near  bottom  of  concrete.  These 
measurements  are  in  the  deepest  holes,  but  in  no  place  opposite  pile  is 
there  any  of  the  original  face  of  concrete  left. 

These  measurements  all  assume  the  concrete  berm  to  be  6  inches 
wide;  but  in  aligning  the  lowercourse  of  granite,  the  berm  varied  in 
width  from  5  to  7  inches. 

A  corresponding  variation  ensues  in  the  offset  measurements.  In 
ounding  from  the  top  of  wall  with  a  heavy  boat-hook,  the  soft  upper 
part  of  offset  could  be  distinctly  felt,  and  the  hook  could  be  hooked 
under  the  lower  stone  for  nearly  the  entire  width  of  panel.  After  press- 
ing the  iron  point  down  through  the  soft  concrete  on  the  berm,  it 
struck  firm  concrete  below  (6  inches.  7  inches,  9  inches,  10  inches,  or  12 
below).    (See  Fig.  2,  Plate  I.) 

Sixth  panel  (front),  offset  not  so  much  gone  as  in  fourth  and  fifth 
panels,  but  only  one  patch  about  3  feet  by  2  feet  of  the  entire  panel 
face  shows  original  surface  of  concrete.  Pile  of  concrete  stone  and 
sand  at  toe  of  wall  1  foot  to  2  feet  deep  above  rip-rap. 

Concrete  face  not  so  uneven  as  fourth  and  fifth  panels.  Measure- 
ments at  north  panel  pile  show  hole  in  concrete  about  6  feet  below 
offset,  16  to  17  inches  deep,  and  another,  near  bottom,  Zl/Z  inches  deep. 

At  offset,  no  holes  exist  under  the  stone  ;  offset  averages  about  3 
inches  to  4  inches  in  width,  and  is  soft  on  top  for  some  inches  down,  as 
determined  by  boat-hook  point  from  above.  The  offset  would  not  show 
a  6-inch  berm  below  at  any  point,  the  edge  of  it  being  replaced  by  a 
batten  for  a  straight-edge,  used  for  leveling  the  top  of  concrete  mass 
before  laying  the  stone.    (See  sketch.) 

Seventh  panel  (front  ),  offset  very  good  and  quite  firm,  after  getting 
through  a  few  inches  of  soft  material.  Face  of  concrete  fallen  off  1% 
inches  deep,  2  feet  below  offset. 

Not  off  at  all,  4  feet  below  offset. 

Off  \.yz  inches  deep,  6  feet  below  offset. 

Not  off  at  all,  8  feet  below  offset. 

Not  off  at  all.  10  feet  below  offset.  « 

Face  of  concrete  very  good,  all  over  the  panel  but  some  holes  in 
wall,  not  large  or  deep,  and  none  deeper  than  4  ,4  inches.  Debris,  at 
bottom  of  wall,  about  1  foot  8  inches  deep  above  rip-rap. 

This  could  not  have  come  from  the  crumbling  on  face  of  the  wall, 
but  is  probably  mud. 

Eighth  panel  (frontj.face  of  concrete  better  than  any  preceding 
panels.  Diver  selected  a  smooth  surface  (original  surface),  and  dug  a 
hole  in  with  a  steel  drill.  Hole  about  6  inches  deep  by  6  inches  broad. 
Took  him  about  four  minutes.    Brought  up  a  handful  of  the  concrete 


47 


stone  from  hole.  The  drill  was  of  8-inch  octagon  steel,  21  inches  long, 
edge  H  inches  wide,  and  very  dull. 

At  the  north  panel  pile,  there  is  a  hole  in  face  of  wall  about  2  feet 
wide  and  3  feet  high,  by  6  inches  deep  horizontally.  Top  of  hole,  1  foot 
below  offset.  Other  holes  on  this  face  are  small,  but  along  the  bottom  of 
concrete  the  face  at  toe  of  wall  has  crumbled  off  to  a  depth  (in  face  of 
wall)  of  4  inches  and  height  above  toe  of  wall  of  io  inches  to  12  inches. 
(See  Fig.  3,  plate  I.) 

Ninth  panel  (front),  offset  in  tolerably  fair  state. 

At  2  feet  below,  offset  hole  5  inches  long. 
"  4   "      "         "     face  not  off  at  all. 
"  6   "      "         "       "     '«      "  " 
"  8   "      "         "     hole  8  inches  deep. 
"  10   "      "         "     face  not  off  at  all. 

Face  of  concrete  generally  rather  smooth  and  not  broken  off,  but 
apparently  not  so  hard  as  previous  panels.  In  digging  into  it  with  a 
drill,  however,  it  was  found  to  be  quite  as  hard. 

About  4  feet  above  bottom  of  wall  a  pile-head  is  exposed  on  face  of 
concrete. 

Diver  dug  a  hole  in  original  face  of  concrete  with  a  steel  drill,  5 
feet  below  offset,  in  9  minutes.  Hole  5  inches  deep  and  5  inches 
broad.    Firmest  place  selected  for  this  purpose. 

A  bucketful  of  concrete  stone  was  picked  from  face  of  concrete 
by  the  fingers,  about  1  }4  feet  above  bottom.    (See  Fig.  4,  Plate  I.) 

Tenth  panel  (front,)  offset  not  so  bad,  but  some  of  the  edge  knocked 
off.    Two-thirds  of  face  of  panel  smooth. 

Rubbish  at  foot  of  wall  2  feet  high.  Dug  down  through  rubbish  to 
foot  of  wall,  and  then  dug  into  wall  with  a  hoe  about  4  inches. 
Sound  concrete  here,  better  than  in  any  previous  panel.  At  18  inches 
below  offset,  concrete  at  north  pile  off  to  depth  of  inches,  and 
to  a  width  of  3  feet,  and  a  vertical  height  of  1  foot.  From  that  point 
down  to  toe  of  wall,  no  concrete  off. 

At  middle  of  panel  little  or  no  concrete  off.  straight-edge  fitting 
pretty  close  up  and  down.    (See  Fig  5,  Plate  I.) 

Eleventh  panel  (shutter  still  in  place). 

Twelfth  panel  (front),  face  of  concrete  over  entire  panel,  in  better 
condition  than  any  previously  examined.    Offset  pretty  good. 

At  north  panel  pile,  concrete  off  to  a  depth  of  4  inches  about  \]/2  feet 
below  offset,  extending  across  to  south  panel  pile.  This  is  probably 
the  soft  concrete  formed  under  the  batten  at  top  of  concrete  to  receive 
straight-edge.  At  9  feet  below  offset,  concrete  soft  and  off  a  little  ;  dug 
a  hole  8  feet  below  offset,  5  inches  deep  and  5  inches  broad  with  drill  in 


48 


seven-and-a-half  minutes ;  concrete  harder  than  in  holes  previously 
dug. 

Could  not  pick  out  concrete  stone  with  fingers.  Concrete  stone,  sand 
and  mud,  about  2  feet  deep,  over  rip-rap,  at  toe  of  wall. 

Dug  through  this  debris  and  got  at  toe  of  wall  at  south  panel  pile, 
and  dug  into  face  of  wall  with  the  hoe  about  9  inches,  for  a  height 
above  bottom  of  2  feet,  and  a  width  of  about  1%  feet. 

Found  concrete  very  poor,  and  could  crumble  off  concrete  stone 
easily  with  fingers.  Went  down  to  broken  stone  foundation,  and  could 
put  hand  under  the  wall. 

Thirteenth  panel  (shutter  still  in  place).  Offset  sounded  with  pick 
from  above,  felt  quite  firm,  after  penetrating  a  few  inches  of  soft 
material. 

Fourteenth  pa?iel  (shutter  still  in  place). 

Fifteenth  panel  (front),  about  half  ot  original  surface  of  concrete 
remains  ;  other  half  off. 
Offset  1 1  inches  wide  : 


2  feet,  be 

4  " 
6  " 


ow  offset,  lyi,  in.  concrete  off. 
"     o  14  " 


3/2 


As  determined 
by  straight- 
edge. 


Dug  a  hole  at  toe  of  wall,  12  inches  deep  in  face  of  wall,  18  inches 
high,  and  20  inches  wide. 

Found  a  pile  about  two  inches  in  from  face  of  wall. 

Concrete  in  hole  quite  soft  ;  could  pick  off  concrete  stone  easily  with 
fingers.    Concrete  around  head  of  pile  pretty  firm. 

Dug  hole  with  steel  drill  at  south  panel  pile  6  feet  below  offset,  9 
inches  deep,  and  7  inches  broad,  in  n  minutes.  Concrete  not  so  soft 
as  some  heretofore  examined.  The  hole  was  located  on  a  smooth  con- 
crete surface.    (See  Fig.  6,  Plate  I.) 

Sixteenth  panel  (front),  covered  by  temporary  coffer-dam,  and  not 
examined. 

Seventeenth  panel  (front),  offset  very  good,  and  face  of  concrete 
same.  Good  face  on  about  two-thirds  of  panel — in  bad  order  at  the 
bottom  ;  3  piles  of  outer  row  exposed  ;  could  reach  nearly  around  one 
of  them. 

Near  north  side  of  panel,  measured  in  horizontal  from  straight-edge. 
Offset  10  inches  wide. 


2  feet  down,  3  inches  concrete  off. 
4    "      "     o  " 


49 


6  feet  down,  o  inches  concrete  off. 

8    "     •«       X  " 
io   "     "     6j4  " 

Below  this  the  toe  of  wall  is  broken  under  badly.    Put  in  a  rod 
twenty-three  inches  horizontally  into  wall  where  concrete  was  off. 
Near  the  south  panel  pile  the  offset  is  1 1  inches  wide. 

2  feet  down,  1 1  inches  concrete  off. 
4    ««      «       9y2  « 
6   "     "      2  " 

8     <«       «         2^  " 

io    "      "       9^  " 

Below  this  the  diver  dug  out  a  hole  in  toe  of  wall,  and  could  easily 
pick  off  concrete  stone  with  fingers.    (See  Figs.  7  and  8,  Plate  I.) 

At  south  side  of  this  panel  could  run  a  thin  stick  under  lower  course 
of  granite  4^  inches. 

Eighteenth  panel  (front),  offset  very  good,  but  the  cavity  found 
under  the  lower  course  of  granite  at  north  panel  pile  extended  south- 
wardly to  south  panel  pile.  At  south  pile  it  is  2  inches  deep,  2  feet 
north  4  inches  deep,  4  feet  north  9^  inches  deep,  6  feet  north  19  inches 
deep,  and  at  the  north  panel  pile  stick  went  in  under  stone  22^  inches. 
Cavity  1%  inches  wide  vertically  at  north  panel  pile  ;  not  so  wide  else- 
where. About  half  the  face  of  the  concrete  is  smooth  ;  the  rest  pretty 
rough. 

Concrete  at  bottom  of  panel  badly  broken  off,  and  easily  broken  off 
with  fingers.  At  bottom  found  one  pile-head  exposed  for  half  its  thick- 
ness. Wherever  concrete  is  found  on  top  of  pile-head,  it  appears  to  be 
harder  than  elsewhere,  having  been  more  compressed. 

Horizontal  measurements  were  taken  at  north  pile  where  offset  is  12 
inches  wide. 

2    feet    down,  6    inches    concrete  gone, 
4     "  o 
6  o 
8  "        "4  " 
10     "        "  3 

At  south  panel  pile  or  near  it,  the  offset  is  12  inches  wide. 

2    feet    down,   11    inches    concrete  off. 
4  "  6 


50 


At  toe  of  wall  at  south  panel  pile,  hole  in  wall  22  inches  deep,  hori- 
zontally. 

Dug  hole  6  feet  below  offset  in  middle  of  panel  in  7  minutes,  6  inches 
deep  and  seven  inches  wide.    (See  Figs.  9  and  10,  Plate  I.) 
Nineteenth  panel  (shutter  yet  in). 

It  will  be  observed  that  no  bad  seams  were  reported  by  the  diver 
during  the  examination  above  described.  Another  examination  ot  the 
front  of  the  wall  was  made  about  seven  weeks  later,  on  the  9th  and  10th 
of  December,  with  the  assistance  of  Diver  Conklin.  who  had  been  em- 
ployed in  finishing  the  inspection  of  the  Canal  Street  wall. 

The  object  of  this  second  examination  was  to  check  the  previous  one, 
as  well  as  to  ascertain  whether  any  extensive  seams  of  laitance  and 
river  filth,  such  as  characterized  the  Canal  Street  wall,  were  to  be  found 
in  the  King  Street  structure.  The  notes  of  this  second  inspection  are 
given  below. 


Second  Examination  of  the  front  of  the  King  Street   Wall,  by  Q. 
A.  Gillmore,  assisted  by  Diver  T.   W.  Conklin. 

Fourth  panel  (front),  examined  the  wall  up  to  down  the  middle  of 
panel,  with  a  steel  probe,  and  could  find  no  seams.  Face  gone  all  over 
the  panel.  Two  foundation  piles  exposed  near  the  north  panel  pile. 
Could  not  push  the  probe  in  anywhere  in  this  panel. 

Fifth  panel  (front),  could  .find  no  seams  with  the  steel  probe. 
Nearly  the  whole  face  of  this  panel  is  rough  and  crumbled  off,  and  con- 
crete could  be  crumbled  off  by  rubbing  it  with  the  hand.  No  meas- 
urements of  depth  were  taken. 

Sixth  panel  (front),  same  record  as  the  fifth. 

Seventh  panel  (front),  same  record  as  the  fifth. 

Eighth  panel  (front),  no  seams.  The  face  is  smooth  down  8  feet 
from  top.  Below  that  the  toe  of  wall  is  caved  under  several  inches,  all 
the  way  across  panel.  There  is  no  hard  scale  on  the  face  of  the  con- 
crete, like  that  found  on  the  Canal  Street  wall. 

Ninth  panel  (front),  found  no  seams  with  the  steel  probe.  Four  feet 
down  fr^.m  top,  soft  but  smooth.  Below  that  scaled  off  considerably  in 
places,  but  no  measurements  of  depth  taken. 

Tenth  panel  (front),  on  north  side,  3  feet  down,  found  a  place  4  to  6 
inches  wide,  and  2 ]/2  feet  long,  where  the  probe  went  in  from  6  to  9 
inches.  Rest  of  panel  scaled  off  some,  but  no  measurements  taken. 

Twelfth  panel  (front),  at  18  inches  below  offset,  in  the  middle  of  the 
panel,  the  probe  was  pushed  in  by  hand  9  inches  into  the  original  face  of 
the  concrete.    Face  of  entire  panel  pretty  good  generally.    There  is  a 


51 


seam,  about  4  feet  clown  from  the  top,  about  the  middle  of  the  panel,  r 
inch  wide  and  2  feet  long,  into  which  the  probe  went  17  inches. 

Fifteenth  panel  (front),  upper  half  pretty  good  and  very  little  of  face 
off.  Lower  half  very  soft.  Can  run  probe  in  6,  9  and  12  inches  in 
many  places  in  lower  half.  No  seams  were  found.  Could  easily  pick 
off  concrete  stone  with  the  fingers. 

Seventeenth  panel  (front),  face  pretty  good  on  the  upper  half,  but 
badly  broken  under  at  the  bottom,  near  the  north  side  of  panel.  Run 
the  probe  into  cavity  4  feet  in  one  place.  The  height  of  break  reaches 
to  about  6  inches  above  the  heads  of  outer  row  of  piles.  Could  rub  off 
concrete  stones  with  hand  easily.  Could  not  run  the  probe  into  con- 
crete anywhere ;  it  was  always  stopped  by  the  stones.  No  seams 
were  found. 

Eighteenth  panel  (front),  could  pick  off  the  concrete  stones  easily. 
It  falls  off  the  face  of  wall  by  rubbing  the  hand  over  it.  Probe  cannot 
be  pushed  in  on  account  of  concrete  stones.  Bottom  of  panel  badly- 
caved  under,  all  across  the  panel  ;  in  one  place  can  reach  under  the 
full  length  of  the  arm. 


Rear  of  King  Street  Wall. 

Examined  by  Q.  A.  Gil hn ore  with  Diver  John  Burt,  October  13th  to 

26th,  1875. 

Nineteenth  panel  (shutter  not  yet  up). 

Eighteenth  panel  (rear),  face  of  concrete  only  9  feet  high  above  rip- 
rap, owing  to  sloping  offset  at  top.  For  7  feet  down  from  top  concrete 
is  smooth,  and  shows  original  face.  Below  that  broke  down  and  under 
badly  for  entire  width  of  panel.  Four  piles  of  outer  row  exposed,  and 
can  be  touched  with  the  hands. 

Can  reach  under  heel  of  wall  18  to  20  inches  for  entire  width  of  panel. 
This  cavity  is  about  2  feet  high.    (See  Fig.  19,  Plate  I.) 

Seventeenth  panel  (rear),  upper  part  of  panel,  for  7  feet  down,  pretty 
good  and  smooth. 

The  lower  two  feet  of  face  caved  off,  for  entire  width  of  panel,  10 
inches  deep  at  north  side,  and  6  inches  at  south,  horizontally.  Felt  2 
piles  at  north  side. 

Made  hole  in  concrete  with  drill,  about  5  feet  down,  on  north  side  of 
panel,  hole  9  inches  deep  and  6  inches  broad,  in  four  minutes  ;  concrete 
very  soft  and  easily  dug  out.    (See  Fig.  18,  Plate  I.) 

Sixteenth  panel  (rear),  face  of  concrete  very  soft  and  not  quite  as 
smooth  as  the  two  previously  examined.    Smoothest  part  reaches  from 


52 


the  top  down  7  feet,  or  2  feet  above  bottom.  The  lower  2  feet  of  face 
caved  off. 

At  north  side  of  panel  cavity  8  inches  deep,  horizontally,  growing 
deeper  toward  south  side,  where  it  is  18  inches  deep.  At  one  point, 
at  south  side,  run  a  stick  2  feet  1 1  inches  under  wall.  Diver  broke  a 
fragment  from  top  edge  of  concrete  face  6  inches  to  8  inches,  by  3 
inches  to  6  inches,  by  5  inches  to  6  inches,  composed  entirely  of  sand, 
cement  and  laitance.  Probable  subsided  washings  of  concrete. 
Concrete  quite  as  soft  as  in  seventeenth  panel.  (See  Fig.  17, 
Plate  I.) 

Fifteenth  panel  (rear),  October  25th.  Good  face  down  to  7  feet 
from  top.  At  that  point  a  long  cavity  occurs,  1  foot  wide  vertically,  reach- 
ing entirely  across  the  panel,  from  6  inches  to  10  inches  deep.  Bottom 
of  wall  better  than  previously  found  on  rear  face. 

Dug  a  hole  near  north  side  of  panel,  4^  feet  down  from  offset,  in  3 
minutes  with  drill,  7>£  inches  deep  (conical),  8  inches  diameter.  (See 
Fig.  16,  Plate  I.) 

Fourteenth  panel  (rear).  October  25th.  Face  good  for  7%.  to  8  feet 
down  from  offset.  There  a  break  occurs  clear  across  heel  of  panel,  8 
inches  deep,  horizontally,  at  north  side  of  panel,  and  1  foot  deep  at 
south  side,  from  1  foot  to  \y2  feet  in  width,  vertically. 

Found  3  piles  exposed  ;  of  2  of  them  could  feel  around  one-third  of 
their  face,  and  of  1,  two-thirds  around.  At  the  break,  named  above, 
concrete  soft.  About  4  feet  down  at  north  side,  dug  conical  hole  in 
face  of  concrete  with  drill,  5  inches  deep  and  5  inches  in  diameter,  in  9 
minutes.  Concrete  much  harder  than  at  any  other  place  yet  examined 
in  rear.    (See  Fig.  15,  Plate  I.) 

Thirteenth  panel  (rear),  October  25th.  Face  pretty  good  down  73^ 
feet  from  offset.  There  a  break  occurs  ;  at  south  end  merely  rough  ;  at 
north  end,  15  inches  deep  horizontally,  and  1  foot  high.  In  the  middle 
of  panel,  about  4  feet  down,  dug  a  hole  with  a  drill,  13  inches  deep  and 
10  inches  in  diameter,  in  6  minutes. 

Twelfth  panel  (rear),  October  25th.  Face  generally  good.  At  south 
pile,  t 8  inches  below^  top,  8  inches  depth  ot  concrete  gone,  18  inches 
wide,  and  running  off  to  nothing  at  a  distance  of  2  feet.  At  north  pile, 
concrete  gone  all  the  way  down  3  inches  or  4  inches  deep,  and  2^  feet 
wide,  horizontally. 

At  heel  of  wall  there  is  a  pile  of  mud  about  2  feet  high.  Dug  into 
the  mud,  and  at  a  depth  of  8  feet  down,  found  a  break  in  base  of  wall, 
5  inches  deep  at  south  side. 

Dug  hole  in  face  about  4  feet  from  top,  with  drill  near  north  side,  12 
inches  deep,  12  inches  diameter  in  5  minutes.  Concrete  quite 
soft. 

Eleventh  panel  (rear),  October  25th.    Face  generally  rough,  the  only 


53 


smooth  part  being  above  a  line  drawn  from  the  top  at  south  pile,  to  a 
point  4  feet  down  at  north  pile  ;  about  2j4  feet  depth  of  mud  at  base. 
(Continued  October  26th.) 

Dug  conical  hole  in  face  with  drill,  3  y2  feet  down,  near  the  north  side. 
5  inches  deep,  6  inches  diameter,  in  9  minutes.  Concrete  pretty  hard, 
relatively. 

Tenth  panel  (rear),  October  26th.  Face  good  above  a  line  drawn 
from  a  point  4  feet  down  at  south  pile,  to  a  point  8  feet  down  at  north 
pile,  the  line  being  crooked.    (See  sketch.) 

Below  this  smooth  face  a  break  is  found  at  south  pile,  where  the  con- 
crete is  off  to  a  depth  of  12  inches,  extending  from  smooth  face  to  bot- 
tom, and  in  breadth  extending  over  to  north  pile.  (See  shaded  part  of 
sketch.) 

Dug  hole  with  drill  near  north  side,  4  feet  down,  5  inches  deep,  5 
inches  diameter,  in  5  minutes;  concrete  soft.    (See  Fig.  14,  Plate  I.) 

Ninth  panel  (rear),  October  26th.  Face  good  down  to  8  feet  from 
offset,  where  there  is  a  break  extending  entirely  across  panel,  8  inches 
deep  at  south  side,  merely  rough  in  middle,  and  4  inches  deep  at  north 
side,  and  1  foot  high  all  along  from  pile  to  pile. 

At  north  pile,  4  feet  from  top,  a  piece  is  out,  making  a  hole  6  inches 
deep,  1  foot  wide  and  iX  ^ett  high . 

Dug  conical  hole  in  face,  about  4  feet  down,  near  north  side,  6  inches 
deep,  and  7  inches  diameter,  in  7  minutes.    (See  Fig.  13,  Plate  I.) 

Eighth  panel  (rear),  October  26th.  Face  of  concrete  pretty  good  all 
the  way  down.  The  hole,  mentioned  on  the  north  side  of  ninth  panel, 
extends  through  into  the  eighth,  and  is  about  4  inches  deep  horizon- 
tally, and  1  foot  high  and  1  loot  broad. 

Could  find  no  break  at  foot  of  wall  ;  but  the  concrete  is  soft,  and  con- 
crete stone  easily  pulled  out  with  the  fingers.  About  2  feet  depth  of 
mud  at  base  of  wall  ;  could  easily  thrust  the  arm  through  it  to  base  of 
wall. 

Dug  a  hole,  3  feet  down  at  north  side  6^  inches  deep,  about  7  inches 
broad,  in  6  minutes  ,  hole  nearly  round  on  the  face.  Could  easily  pick 
out  concrete  stone  with  the  fingers. 

Seventh  panel  (rear),  October  26th.  Face  pretty  gcod  down  to  7  feet ; 
there  it  is  rough  at  the  south  pile.  In  middle  4  inches  in  depth  gone  ; 
north  side  smooth.  About  8  feet  down  in  middle  of  panel  (for  one- 
third  its  width)  gone  to  depth  horizontally  of  8  inches  ;  18  inches  depth 
of  mud  at  base.  At  south  pile  on  top  at  offset,  a  piece  gone  2l/z  feet 
long,  lengthwise  of  wall,  18  inches  wide  and  10  inches  thick,  of  wedge 
shape. 

(See  shaded  area  at  x.) 

Probably  a  piece  broken  off  as  a  sample,  or  accidentally  in  removing 
shutters. 


54 


Dug  a  hole  y/2  feet  down,  near  north  side,  inches  deep,  6  inches 
diameter,  in  8  minutes.    (See  Fig.  12,  Plate  I.) 

Sixth  panel  (rear),  October  26th.    Face  pretty  good  all  over.  About 

3  feet  down,  at  south  pile,  concrete  gone  6  inches  deep,  10  inches  wide 
and  18  inches  in  length.  From  12  to  18  inches  depth  of  mud  at  base 
of  wall.    Felt  well  along  the  heel  of  wall,  and  found  it  in  good  order. 

Dug  hole  in  face  2>lA  feet  down,  near  north  side,  10  inches  deep,  and 
10  inches  in  diameter,  in  6  minutes.    Quite  soft. 

Fifth  panel  (rear),  October  26th.  Face  generally  smooth.  Small 
pieces  chipped  off  upper  edge  at  offset.  At  a  point  y/2  feet  down,  con- 
crete gone  at  south  side,  6  inches  deep,  18  inches  in  lergth,  and  12 
inches  in  width.  Remainder  of  panel  good  to  bottom  ;  the  best  that  had 
been  examined  in  the  rear.  About  10  inches  depth  of  mud  at  heel  of  wall. 

Dug  hole  4  feet  down,  on  north  side  of  panel,  7  inches  deep  and  7 
inches  in  diameter,  in  5  minutes.    (See  Fig.  11,  Plate  I.) 

Fourth  panel  (rear),  October  26th.  Face  good.  About  8  feet  down, 
found  an  opening  or  horizontal  crack  18  inches  long,  about  middle  of 
panel.  Could  just  pass  the  hand  in.  Found  the  concrete  soft.  Opened 
a  place  1  foot  square  and  4  or  5  inches  deep  with  his  hand.    Dug  hole 

4  feet  down,  near  north  side,  6  inches  deep,  9  inches  diameter,  in  7 
minutes.    Not  so  soft  as  in  some  other  places. 

Third  panel  (rear),  October  26th.  Good  face  for  two-thirds  of  sur- 
face. Roughened  at  each  pile.  Corners  gone  where  bottom  was  on 
pile.  About  7 '4  feet  down  in  middle,  found  horizontal  crack,  3  feet 
long.   Could  pass  hand  in  5  inches  and  pull  out  stone. 

Dug  a  hole  in  face  4  feet  down,  near  north  side,  7  inches  deep,  7 
inches  diameter,  in  3  minutes.  Dug  a  hole  8  feet  down  near  south 
side,  6  inches  deep,  7  inches  across,  in  3  minutes.  Concrete  about  same 
hardness  in  both  places. 

Second  panel  (rear),  October  26th.  Face  rough  on  upper  part  down 
to  7  feet.  Roughness  apparently  not  over  4  inches  or  5  inches  deep. 
Bottom  apparently  smooth,  as  felt  through  about  2  feet  of  mud. 

Dug  hole  3  feet  down  near  north  side,  1 1  inches  deep  and  8  inches 
across,  in  3  minutes.  About  8  feet  down,  near  south  side,  dug  a  hole,  5 
inches  deep  and  7  inches  across,  in  4  minutes.  Apparently  harder  than 
in  the  hole  above. 

First  panel  (rear).    (Shutter  yet  in.) 


Quay  Wall  Foot  of  Canal  Street,  North  River. 
Inspected  by  Q.  A.  Gillmore,  with  Diver  John  Burt. 
The  panels  are  numbered  from  south  to  north  in  front  and  rear.  (See 
Plate         of  the  joint  report.) 

Rear  Panel  No.  20.    New  work  laid  in  early  part  of  July,  1875. 


55 


White's  cement  in  rear,  Knight,  Bevans  &  Sturges' cement  and  White's 
in  centre  and  front.  Upper  6  feet  rough  and  loose.  General  face 
pretty  good.  3  feet  down  a  seam  about  1  inch  to  \  VZ  inches  wide,  run- 
ning across  face  horizontally.  In  some  places  a  -}^-inch  rod  goes  in  2 
feet  6  inches  on  north  end  ;  south  end  not  so  deep.  Good  then  to  8 
feet  down.  Another  seam  then  1%  inches  to  2  inches  wide  ;  ^-inch 
rod  can  be  run  in  3  feet  in  some  places.  1  foot  further  down  (at  bot- 
tom) hole  produced  by  board,  good,  nicely  rounded  off,  solid  ;  good 
undeineath. 

In  north  side  of  same  panel,  4  feet  down,  dug  a  hole  5  inches  deep, 
about  6  inches  broad,  in  5  minutes.  Concrete  pretty  soft.  Pulled  out 
some  stone  with  fingers  as  soon  as  hole  was  started.  More  like  King 
Street  Wall,  except  the  face,  which  is  harder  and  smoother.  (See  Fig. 
1,  Plate  II.) 

Rear  Panel  No.  24.  About  6  inches  down  from  the  top  a  piece  of 
scantling  lying  on  wall,  leaving  the  top  rough  and  broken.  About  1 
foot  below  the  top,  there  is  a  seam  running  underneath  the  scantling 
horizontally,  2  to  3  inches  in  width  ;  rod  goes  in  whole  length  of  3  feet. 
3  feet  down  another  horizontal  seam  1  \/2  inches  wide  ;  bar  went  in  5 
inches.  7  feet  down  from  top  a  small  seam  scant  1  inch  in  width  ;  rod 
went  in  about  3  inches. 

General  face  pretty  good.  l\1/2  feet  down  on  north  side  drilled  hole, 
5  inches  deep  and  7  inches  in  diameter,  in  6  minutes.  Not  so  soft  as 
in  previous  panel.  Picked  stone  out  with  fingers.  Concrete  pretty 
good  at  bottom.    Whole  height  examined,  %)/z  feet.    (Fig.  2,  Plate  II.) 

Rear  Panel  No.  13.  Partially  examined  by  Mr.  Worthen.  Begun 
where  his  work  stopped  the  day  before.  Upper  edge  slightly  broken. 
About  2  feet  down  a  horizontal  seam  across  face  of  panel,  2  inches 
wide  and  4  inches  deep.  5  feet  down,  good.  Then  a  break  takes 
place,  about  5  inches  deep,  for  2V2  feet  down.  Remainder  rough,  but 
full.    Nothing  lost  at  heel. 

Drilled  hole  about  3  feet  down  in  smooth  part,  4^  inches  deep  and  4 
inch  diameter,  in  6  minutes.  This  was  on  north  side  of  panel.  Soft- 
est concrete  yet  tried  as  shown  by  drilling.    (Fig.  3,  Plate  II.) 

Rear  Panel  No.  14.  Upper  edge  good.  \)/2  feet  down  a  horizon- 
tal seam  across  the  face,  width  1  inch,  depth  4  inches.  5  feet  down 
from  top  on  south  side,  a  break  occurs  extending  horizontally  over  % 
of  panel,  and  vertically  2  feet.    Deepest  part  of  break,  4  inches. 

On  north  side,  5  feet  down,  a  seam  occurs  1  y2  inches  wide  and  8 
inches  deep.  Remainder  of  panel  not  smooth  but  good  for  8  feet 
down  ;  cannot  get  down  the  other  foot  owing  to  rip-rap.  (See  Fig.  4, 
Plate  II.) 

Rear  Panel  No.  1 5.  First  one  foot  down,  pretty  good,  then  a  seam, 
^  inch  wide  ;  rod  went  in  3  to  4  inches.    Then  good  to  4^  feet  from 


50 


top,  where  another  seam  occurs,  almost  horizontal,  I  ]/z  inches  wide 
and  6  inches  deep.  feet  down  there  is  a  break,  depth  of  break 

about  4  inches,  extending  about  9  inches  along  face  of  panel.  Rough, 
but  pretty  good  below  this.  General  character  of  face  good.  Got 
down  yi/2  feet  on  this  panel.  Drilled  hole  24  feet  down,  2}4  inches 
deep,  about  3  inches  diameter,  in  6  minutes.  Very  hard.  (See  Fig. 
5,  Plate  II.) 

Rear  Pa7iel  No.  16.  Diver  down  20  minutes.  2  feet  down  there  is 
a  small  horizontal  seam  1  inch  wide,  about  5  inches  deep.  Down  to  7 
feet  from  top,  good  ;  then  another  seam  goes  across  the  face  \]4  inches 
wide  and  finches  deep.  Underneath  this  seam,  the  north  side  of 
panel  is  broken  down,  and  4  piles  exposed,  the  north  pile  being  18 
inches  from  face  of  wall,  and  the  others  gradually  coming  nearer  to 
face. 

General  character  of  the  face  good.    (Fig.  6,  Plate  II.) 

Rear  Panel  No.  17.  Upper  part  not  very  good  for  1  foot  down, 
then  a  seam,  running  across  horizontally,  1  inch  wide  and  4  inches  deep. 
3  feet  from  top  for  2  feet  down,  wall  rough  but  pretty  good.  From  that 
to  7  feet  down  good,  then  broken  away  1  foot  deep  at  north  end  and  6 
inches  at  south  end. 

Felt  one  pile  at  south  end,  part  of  it  in  concrete.  Smooth  head,  can 
put  hand  partly  round.  Drilled  hole  in  rough  part  of  wall  at  north  end 
of  panel,  about  y/2  feet  from  top,  in  5  minutes,  9  inches  deep  and  7 
inches  in  diameter.  Very  soft.  Could  pull  out  stone,  due  perhaps  to 
seam  running  across.    (  Fig.  11,  Plate  II.) 

Rear  Panel  No.  18.  Upper  part  little  better  than  previous  panel. 
One  foot  down  a  seam,  1  inch  wide  and  4  inches  deep.  3  feet  down 
another  seam,  1  yz  inches  wide  and  6  inches  deep.  Wall  pretty  good 
down  to  seven  feet,  then  broken  in  badly.  Can  reach  in  3  feet  at  bot- 
tom (or  9  feet  down  from  top.)  Felt  4  piles ;  middle  one  flush,  with 
original  concrete  face  ;  south  pile  further  in,  about  2  inches.  General 
character  of  face  pretty  good  above  this  break.  (See  Fig  10, 
Plate  II.) 

Rear  Pane!  No.  19.  Upper  part  not  very  good  for  1  foot  down. 
Then  comes  a  seam  1  inch  wide  and  5  inches  deep.  Then  pretty  good 
below,  for  a  distance  of  iVz  feet  from  top.  Then  another  seam  3 inches 
wide  and  2  feet  deep  at  nonh  end,  and  1  foot  deep  at  south  end.  Below 
that,  down  to  7  feet  from  top,  wall  pretty  good,  but  rough.  Then  a 
deep  break  cccurs.  Could  find  2  piles  pretty  well  in.  Can  reach  in  3 
feet  with  bar  at  the  bottom.    (See  Fig.  9,  Plate  II.) 

Dug  hole  4  feet  down  on  north  side,  3  inches  in  width  and  3  inches  in 
depth,  in  6  minutes. 

Rear  Panel  No.  27.  From  top  2><  feet  down  very  soft,  like  putty. 
Rod  goes  in  full  length  of  3  feet,  horizontally,  into  concrete,  for  dis- 


57 


tance  of  2  feet  down.  Then  rough  I  foot  down,  but  not  so  soft. 
Thence'good  to  bottom.    Lower  6  feet  good.    Old  work,  perhaps? 

At  2  feet  down,  dug  out  a  bucketful  of  concrete  with  trowel.  Soft 
mortar  only  and  no  stone.  This  was  taken  2  feet  below  a  batten  left 
on  piles  for  straight-edge  for  leveling  off  top  of  concrete. 

There  appears  to  have  been  no  slope  made  on  rear  upper  corner  of 
concrete  mass  at  this  place,  as  the  face  of  wall  reached  up  to  the  bat- 
ten placed  for  leveling  off,  and  this  batten  was  only  II  feet  above  bot- 
tom of  wall  apparently.  Possibly,  diver  did  not  reach  bottom  by  I  foot, 
which  would  make  batten  in  right  place.  Dug  a  hole  in  wall,  2  feet 
from  bottom  at  south  side,  6yz  inches  deep  and  6  inches  diameter,  in 
five  minutes.  Best  bottom  (or  one  of  the  best)  for  smoothness  yet 
examined  rear  of  this  wall.    (See  Fig.  8,  Plate  II.) 

Rear  Panel  No.  32.  From  top,  soft  8  inches  down.  Face  seems 
quite  good  for  6V2  feet  down,  with  soft  places  in  it.  From  6y2  feet  to 
7)4  feet,  soft  right  across  the  face  horizontally. 

About  8  to  %y2  feet  down  the  south  end  of  panel  is  very  soft ;  this  is  a 
seam  ;  diver  can  put  his  hand  in.  There  is  a  face  to  the  wall,  but  it  is 
very  soft.  Got  down  to  the  bottom.  General  character  of  face 
smooth  but  soft.  Dug  hole  in  face,  4  feet  down  on  north  side  of  panel, 
6  inches  deep,  6  inches  diameter,  in  five  minutes. 

Prettv  soft  ;  could  find  very  few  concrete  stones. 


REMARKS. 

First.  Portland  cement,  with  respect  to  the  amount  of  clay — that  is, 
silica  and  alumina — which  the  artificial  mixture  or  the  natural  stone 
contains  previous  to  burning,  occupies  an  intermediate  place  between 
the  ordinary  hydraulic  limes  of  commerce  used  throughout  Europe,  and 
the  quick-setting  argillaceous  and  argillo-magnesian  cements,  such  as 
the  Roman,  the  Vassy,  the  Rosendale,  the  Cumberland,  and  other  Ameri- 
can cements.  The  hydraulic  limes  contain  less  clay  than  the  Portland 
cement,  and  the  quick-setting  cements  more. 

Second.  During  the  burning  of  a  stone  which  yields  hydraulic  lime, 
all  the  silica  and  alumina  combine  with  lime,  producing  silicate  of  lime, 
silicate  of  alumina,  aluminate  of  lime,  and  other  combinations.  These 
are  the  compounds,  which,  after  water  is  added,  undergo  a  species  of 
crystalization,  technically  called  setting,  which  constitutes  the  hydrau- 
lic property.  But  there  is  in  the  burnt  product  an  excess  of  uncom- 
bined  or  quick  lime,  sufficient  to  cause  it  to  slake  to  powder  in  the 
presence  of  water,  in  the  same  manner  as  common  lime  slakes,  though 
much  less  promptly,  especially  if  the  excess  of  quicklime  be  small.  A 


58 


paste  of  hydraulic  lime  is  somewhat  unctuous  to  the  touch,  and  sticky 
and  soapy,  although  less  so  than  a  paste  of  common  lime.  When  a 
mass  of  it  is  placed  in  water,  it  will  gradually  enlarge  itself  laterally  by- 
spreading  out  in  all  directions  in  consequence  of  its  weight  and  plas- 
ticity. In  doing  so,  it  will  usually  present  the  same  surface  constantly 
to  the  water,  and  will  not  crack  up  into  numerous  pieces,  or  fall  asun- 
der into  a  lumpy  or  granulated  mass.  Hence  a  mortar  of  hydrau- 
lic lime,  if  quietly  deposited  under  water,  will  not  generally  become 
washed  out  so  badly  as  to  separate  the  sand  from  the  lime,  but  the  par- 
ticles of  sand  will  be  mechanically  held  in  place  by  the  lime  paste 
during  the  time  while  the  mass  is  assuming  a  state  of  rest  and  equili- 
brium, after  which  it  will  gradually  indurate  by  setting.  The  water 
must  be  as  quiet  as  possible,  and  all  currents  that  might  wash  away 
the  lime  from  the  sand  be  avoided. 

Third.  When  a  hydraulic  lime,  after  burning,  cannot  be  slaked  to 
a  powder  or  paste  with  water,  but  must  be  reduced  by  grinding,  it 
is  called  a  cement ;  and,  if  it  contain  certain  proportions  of  silica,  alu- 
mina and  lime,  it  will  yield  Portland  cement.  The  composition  of  a 
mixture,  whether  natural  or  artificial,  that  will  produce  Portland 
cement,  is  such  that,  when  burned  at  a  high  heat,  the  silica,  alumina 
and  lime  enter  into  combinations  with  each  other,  and  form  those 
combinations  which  confer  the  hydraulic  energy,  leaving  neither 
ingredient  in  excess  as  an  adulterating  constituent.  It  is  to  this  cir- 
cumstance, in  part,  that  Portland  cement  owes  its  superiority.  When 
finely  ground,  a  heavy,  sharp,  and  minutely  granulated  powder  (the 
Portland  cement  of  commerce)  is  produced.  If  mixed  with  water  into 
a  stiff  paste,  it  is,  in  great  measure,  destitute  of  those  unctuous  and 
adhesive  properties  which  characterize  a  paste  of  common  or  hydraulic 
lime.  It  may  be  said  to  possess  little  cohesiveness  until  it  begins  to 
set,  which  ensues  two,  three  or  four  hours  after  mixing,  depending  on 
its  qualities.  A  plastic  cake  of  it,  immersed  in  water,  will  not  gradually 
spread  itself  out  in  the  same  manner  as  the  lime  paste,  but  will,  unless 
it  be  rather  flat  and  thin,  with  gentle  slopes  on  all  sides,  break  down  all 
around  by  the  sliding  off,  successively,  of  the  exterior  portions,  thus 
constantly  presenting  a  new  surface  to  the  wash  of  the  surrounding 
water,  until  it  attains  the  angle  of  repose.  When  the  cake  is  of  such 
form  that  no  cracking  or  disintegration  takes  place  when  immersed — 
that  is,  when  it  is  comparatively  flat  and  broad — it  will  set  and  harden 
with  great  energy  under  water.  Indeed,  the  most  advantageous  con- 
ditions for  its  hardening  are  secured  in  the  water,  or  in  a  constantly 
wet  place,  provided  the  initial  set  can  begin  in  the  open  air,  or  the 
immersion  can  be  made  without  drowning  out  the  material,  which 
always  results  in  separating  the  finer  from  the  coarser  particles,  and  the 
loss  of  the  former,  in  a  greater  or  less  degree,  in  the  form  of  laitance, 


59 


and  in  the  case  of  mortar  in  the  separation  of  the  cement  from  the  sand, 
and  the  deposition  of  each  material  in  layers  or  pockets  by  itself.  In 
this  process  the  sand,  being  the  heavier  of  the  two,  will  go  to  the  bot- 
tom. The  evil  results  are  more  serious  with  the  slow  than  with  the 
quick-setting  pure  cements,  for  the  simple  reason  that  the  disintegra- 
tion is  arrested  as  soon  as  the  induration  fairly  begins.  When  any 
kind  of  hydraulic  cement,  or  cement-concrete,  is  deposited  in  water, 
some  of  its  lighter  particles  are  washed  out  and  held  for  a  time  in  sus- 
pension in  the  water.  They  afterwards  subside  as  a  layer  upon  the 
top  of  the  mortar  or  concrete,  and,  if  not  removed,  interpose  themselves 
between  contiguous  layers.  As  they  possess  very  little,  if  any, 
hydraulic  energy,  they  are  elements  of  weakness  in  the  mass  in  pre- 
venting the  requisite  continuity  and  bond.  The  French  engineers  call 
this  material  laitance.  It  is  not  only  an  injury  in  itself  by  producing 
seams  in  the  mass,  but  it  injures  the  quality  of  the  cement  from  which 
it  is  extracted.  Its  volume  will  be  great  in  proportion  to  the  amount  of 
washing  to  which  the  mortar  is  subjected  in  the  process  of  its  deposi- 
tion. Some  cements  receive  more  injury  by  washing,  and  yield  more 
laitance  than  others. 

Fourth.  When  the  Roman  or  the  Rosendale  cements,  and  cements 
of  like  character,  are  burnt,  all,  or  nearly  all,  of  the  lime  and  magnesia 
which  they  contain  enter  into  combination,  with  the  silica  and  alumnia 
of  the  clay,  in  the  formation  of  those  compounds  which  confer  the 
hydraulic  properties,  leaving,  however,  an  excess  of  uncombined  clayf 
which  acts  as  an  adulterating  ingredient  in  the  cement.  The  burning 
takes  place  at  a  lower  heat,  and  the  compounds  formed  crystalize  a  set 
more  promptly  than  those  of  Portland  cement.  The  free  or  uncombined 
clay  in  the  product  renders  the  paste  ot  these  low-burnt  cements  some- 
what unctuous,  cohesive  and  sticky.  The  powder  is  less  granular,  and 
possesses  much  less  weight  than  Portland  cement,  and,  when  made  into 
mortar,  it  seems  to  hold  the  sand  better.  If  this  is  not,  in  fact,  the  case 
to  any  great  degree,  its  quick-setting  properties  render  it  superior  to 
a  cement  that  sets  slowly,  for  all  kinds  of  submarine  work  where  the 
mortar  has  to  be  immersed  in  the  plastic  state.  Rosendale  cement  of 
active  quality,  if  made  into  a  plastic  ball  or  sphere  of  ^  inch  to  i  inch 
in  diameter,  and  immersed  in  water,  will  harden  without  rupture  or 
change  of  form,  and,  at  the  end  of  about  an  hour,  can  be  rolled  across 
a  room  upon  the  floor  without  breaking. 

No  good  Portland  cement  will  sustain  this  test  ;  yet,  if  both  be 
allowed  to  set  in  the  air,  and  are  then  placed  under  water,  or  in  a  damp 
place  for  five  or  six  days,  the  Portland  cement,  mixed  with  three  and 
a-half  times  its  volume  of  sand,  will  make  as  strong  a  mortar  as  Rosen- 
dale cement  without  sand. 

M.  Leblanc,  Engineer  des  Ponts  et  Chaussees  (see  Annales  for  1865) 


GO 


says  that  heavy  Portland  cement  only,  such  as  weighs  not  less  than  105 
pounds  to  the  struck  bushel,  should  be  used  for  important  works — a 
statement  which  he  could  not  have  made  had  he  been  familiar  with  the 
best  American  cements,  and  the  history  and  results  of  their  use  upon 
our  public  works  during  the  last  forty  years.  I  have  been  a  constant 
advocate  of  Portland  cement  as  a  substitute  for  Rosendale  for  general 
use,  with  certain  marked  exceptions,  for  the  reason  that,  when  very 
strong  work  is  required,  its  superior  strength  gives  it  a  great  advantage, 
while  for  common  masonry,  in  large  masses,  where  inertia  is  desired 
rather  than  strength,  it  will  bear  adulteration  with  common  lime  and 
sand  to  such  degree  as  to  bring  the  cost  of  the  work  even  below  the 
cheapest  that  can  be  produced  with  the  Rosendale,  or  any  equivalent 
American  cement.  For  the  fabrication  of  concrete,  however,  to  be 
deposited  to  take  its  first  set  in  water,  I  have  never  recommended  it, 
not  because  it  is  incapable  of  yielding  excellent  work  under  such  cir- 
cumstances, but  because  the  condiiions,  necessary  to  secure  excellence, 
can  only  be  established  and  maintained  under  the  most  careful  per- 
sonal supervision,  such  as  a  superintending  engineer  is  seldom  able  to 
give.  When  those  conditions  can  be  secured  there  is  no  doubt  of  its 
superiority  to  Rosendale,  or  any  other  light,  quick-setting  cement.  M. 
Leblanc  further  states,  that  Portland  cement  concrete,  immersed  in 
water,  undergoes  an  energetic  weakening,  or  washing-out  ;  that  the 
broken  stone,  as  soon  as  it  touches  the  water,  is  deprived  of  its  mortar, 
in  fact,  keeps  no  trace  of  it ;  that  Portland  mortar  is  not  fat  and  soapy 
like  lime  mortar,  and  does  not  stick  to  the  trowel ;  that,  poured  into  sea 
water,  this  concrete  arranges  itself  in  three  parts  or  beds,  the  upper 
portion  being  a  thick,  milky  solution,  with  no  power  to  set,  and  remain- 
ing soapy  unless  dried.  The  second  portion  resembles  meagre  mortar. 
The  lower  stratum  alone  appears  to  preserve  its  quality  ;  but  being  com- 
posed of  the  heaviest  and  most  highly  burned  grains,  it  sets  very  slowly, 
and,  besides,  is  weakened  by  mixture  with  the  larger  proportion  of 
gravel  forming  the  mortar,  which  talis  down  with  it  through  the  inter- 
stices of  the  broken  stone.  M.  Leblanc  also  remarks  that,  when  con- 
crete is  deposited  in  water  from  boxes,  they  should  be  as  large  as  prac- 
ticable, but  that  if  it  be  absolutely  necessary  to  use  it  under  water,  it  is 
best  to  employ  a  tremie  in  preference  to  any  other  apparatus  ;  also,  that 
Portland  concrete  may  be  spread  out  under  water  with  less  alteration 
than  a  bed  of  lime  mortar  concrete,  provided,  that  steep  slopes  and  the 
rolling  of  the  stones  on  the  surface  are  avoided, which  can  be  accomplished 
sufficiently  easy  with  the  tremie.  It  is  not  attempted  to  give  a  transla- 
tion of  M.  Leblanc's  paper,  but  only  a  summary  of  his  opinions,  so  far  as 
they  bear  upon  the  subject  under  consideration.  He  is  an  advocate  of 
the  use  of  freshly-mixed  Portland  concrete  in  the  water,  under  such  pre- 
cautions as  will  secure  it  against  injurious  wash. 


tt 

Fifth.  It  will  be  inferred  from  the  foregoing-  that,  in  order  to  produce 
good  submarine  masonry  by  depositing  freshly-mixed  concrete  in  the 
water,  certain  precautions  are  necessary,  viz.  : 

(a.)  The  cementing  material  should  possess  the  properties  of  unc- 
uousness  and  adhesiveness  to  enable  it  to  retain  the  sand  while  the 
concrete  is  assuming  a  state  of  rest  in  the  water  ;  and  it  should  be  able, 
in  as  great  degree  as  possible,  to  assume  that  state,  by  flattening  out 
and  spreading,  rather  than  by  breaking  down  and  rolling  off  on  the 
sides  of  the  mass  deposited. 

(&.)  If  it  be  deficient  in  the  properties  last  named,  it  should  in  lieu 
thereof,  be  quick-setting,  in  order  that  the  washing-out  of  the  sand  and 
its  separation  from  the  cement  may  be  arrested  in  a  few  minutes  after 
deposition,  by  the  prompt  induration  of  the  cement. 

(c.)  If  a  box  is  used  for  depositing  the  concrete,  the  torm  of  the  box 
and  the  manner  of  emptying  it  should  be  such  that  the  concrete  will  be 
subjected  to  as  little  wash  as  possible.  Hence,  a  large  box  is  preferable 
to  a  small  one,  as  it  will  expose  a  less  area  of  surface  in  proportion  to 
the  volume  deposited.  For  example,  a  box  3  feet  long  by  3  wide  by  2 
feet  high,  will  hold  18  cubic  feet,  and  has  a  surface  area  of  42  square 
feet,  equal  to  2^3  square  feet  to  each  cubic  foot ;  while  a  box  of  the 
same  form,  but  6  feet  wide  by  6  feet  long  by  4  feet  high,  will  hold  144 
cubic  feet,  and  has  a  surface  area  of  only  168  square  feet,  equal  to 
1  1-6  square  teet  to  each  cubic  foot. 

{d.)  The  form  of  the  box  used  in  laying  the  foundation  of  the  King 
Street  and  Canal  Street  sections  is  objectionable.  It  has  no  cover  on 
top,  so  that  the  exposed  surface  of  the  mixture,  equal  in  itself  to  1 
square  foot  to  every  2  cubic  feet  of  volume,  was  subjected  to  a  rush 
of  water  over  it  during  its  descent  to  the  bottom,  and  the  contents, 
instead  of  being  deposited  in  their  allotted  place  in  a  compact  mass, 
issued  in  a  manner  much  resembling  a  stream.  Moreover,  the  side 
door  of  the  box  fitted  so  imperfectly,  that  the  water  entered  quite 
freely  around  its  edges  and  forced  its  way  through  the  concrete  to 
the  top  before  the  box  became  submerged.  A  box,  operated  on  the 
clam-shell  plan,  would  have  been  better;  but  preferable  to  any  box 
is  the  trimie,  when  properly  constructed  and  operated,  as  the  con- 
crete laid  with  it  never  touches  the  water  until  it  issues  from  the 
bottom  of  the  trd?nie  in  the  spot  where  it  is  to  remain,  without  fur- 
ther disturbance,  except  what  may  be  caused  when  the  next  layer 
is  deposited  upon  it.  It  is  laid  under  a  constant  pressure  from  the 
weight  of  the  column  of  concrete  in  the  trimie  shaft,  which,  with  a 
tremie  20  feet  long,  would  amount  to  abouf  \l/2  tons  per  square  foot. 
A  trimie  is  operated  in  a  vertical  position  and  is  freely  open  at  both 
ends.  The  spout  used  for  a  time  by  the  Department  of  Docks,  was 
closed  at  the  lower  end,  and  the  concrete  issued  in  a  stream  trom  an 


62 


opening  on  one  side.  As  a  matter  of  course,  it  was  badly 
washed. 

Sixth.  A  glance  at  the  inspection  notes  shows  that,  while  the  con- 
crete is  by  no  means  good  in  average  quality,  and  in  many  places  is 
very  bad,  in  the  Canal  Street  and  King  Street  walls,  this  inferiority 
differs  in  the  two  cases,  both  in  kind  and  extent. 

The  Canal  Street  wall  is  traversed  by  several  bad  seams  of  soft 
material,  collected  as  sediment  upon  the  surface  of  some  of  the  layers  of 
concrete,  and,  therefore,  separating  contiguous  layers.  In  some  places, 
a  probe  can  be  thrust  into  this  mixture,  by  hand,  to  a  depth  of  several 
feet,  being  finally  arrested,  apparently,  by  the  broken  stone  in  the  con- 
crete, either  above  or  below.  Much  of  the  material  of  these  seams  is 
entirely  destitute  of  hydraulic  properties,  and  does  not  get  hard  when 
dried,  but  becomes  light,  spongy  and  easily  pulverized  between  the 
fingers.  The  laitance  produced  when  Portland  cement  is  placed  in 
pure  sea  water  is  slightly  hydraulic  and,  although  its  interposition  as 
strata  in  the  concrete  breaks  its  continuity  and  impairs  its  strength  as 
a  monolith,  the  injury  is  trifling  when  the  strata  are  thin  and  few  in 
number,  as  they  always  will  be  when  the  work  is  vigorously  pushed 
with  thick  layers. 

Seventh.  That  portion  of  the  Canal  Street  wall  which  came  under 
my  inspection  was  the  eleven  uncovered  panels  in  the  rear,  situated 
between  the  middle  of  Pier  34  and  the  north  end  of  the  wall.  The 
seams  here  vary  in  width  from  y%  inch  to  3  inches,  and,  in  depth,  as 
ascertained  with  a  probe,  from  3  or  4  inches  up  to  3  feet.  They  are, 
doubtless,  much  deeper  in  some  places  .  but,  as  they  are  interposed 
between  undulating  and  irregular,  instead  of  plane,  surfaces,  the  probe 
would  be  stopped  by  the  broken  stone  of  the  adjacent  concrete.  The 
material  of  the  seams  was  generally  of  a  whitish  color,  composed  mostly 
of  laita7ice,  with  some  river  filth  and  sewage. 

In  several  places,  the  bottom,  or  heel,  of  the  wall  is  broken  under  to  a 
depth  varying  in  the  different  panels  from  1  to  3  feet.  This  is  due  to 
the  relatively  inferior  character  of  the  concrete  composing  the  bottom 
layer,  which,  on  being  emptied  from  the  box,  at  the  pile-heads,  fell 
through  the  water  a  height  of  from  1  to  3  feet  before  it  found  a  resting 
place  on  the  broken  stone.  It  was  therefore  subjected  to  severe 
washing,  and  parted  with  much  of  its  cement  and  sand,  the  lighter  por- 
tion of  the  cement  floating  away  in  the  water,  to  be  subsequently 
deposited  as  a  seam,  while  the  heavier  particles,  together  with  the  sand, 
settled  down  among  the  rubble-stone  below. 

Several  soft  places  were  found  in  the  face  of  the  concrete,  besides  the 
seams  ;  and  some  of  these  contained  no  stone,  but  only  soft  washed-out 
cement,  or  cement  and  sand,  either  mixed  together  or  in  separate  layers. 
These  weak  places  were,  doubtless,  caused  by  the  settlement  of  cement, 


63 


sand  and  laitance  into  the  depressions  next  the  shutters,  left  between 
contiguous  boxes  of  concrete,  thus  filling  these  depressions  or  cavities  to 
such  degree  that  the  concrete  subsequently  deposited  could  not  flow 
into  and  fill  them. 

The  concrete  in  the  heart  of  the  wall,  as  shown  by  the  shaft  sunk 
from  the  top,  is  superior  to  that  on  the  back  next  the  caisson,  and,  with 
the  exception  of  a  few  seams,  is  of  fair  average  quality. 

At  the  King  Street  wall  the  shutters  had  been  removed  from  twelve 
panels  on  the  front,  and  from  seventeen  panels  on  the  rear,  the  whole 
number  of  panels  being  nineteen  on  each  side,  in  a  total  length  of 
146^  feet. 

Diver  Burt  examined  all  the  uncovered  panels  in  front  and  rear.  A 
second  examination  of  those  in  front  was  subsequently  made  by  Diver 
Conklin. 

The  seams  occur  less  frequently,  and  are  fewer  in  number,  and  of  less 
length  along  the  face,  in  the  King  Street  than  in  the  Canal  Street  wall. 
They  are  also  of  less  depth,  as  indicated  by  the  penetration  of  the 
probe  ;  and,  on  the  whole,  do  not  constitute  such  an  element  of  weak- 
ness as  to  require  that  any  special  precautions  should  be  taken  to  guard 
against  it. 

Eighth.  The  hardness  ot  the  concrete  in  the  two  walls  was  fre- 
quently tried,  in  a  rough  way,  by  digging  small  holes  in  the  face, 
care  being  taken  to  select  spots  where  there  was  no  exceptional  soft- 
ness due  to  the  existence  of  seams.  The  instrument  used  was  a  com- 
mon stone  drill,  21  inches  long,  made  from  i-inch  octagon  steel, 
having  on  one  end  a  dull  chisel  edge  %  inch  wide.  It  was  thought 
that,  by  employing  the  same  diver  with  a  similar  drill  at  some  future 
time,  the  progressive  induration  of  the  concrete  could  be  approx- 
imately determined.  The  test-holes  resembled  in  form  the  small  end 
of  an  egg.  The  width  at  the  face  of  the  wall,  and  the  depth,  as 
well  as  the  time  occupied  in  digging  the  hole,  was  recorded  in  each 
case,  and  will  be  found  in  the  notes  of  inspection.  Nineteen  of  these 
holes — five  in  front  and  fourteen  in  rear — were  dug  in  the  King  Street 
wall,  and  eight  in  that  portion  of  the  rear  of  the  Canal  Street  wall, 
which  came  under  my  inspection.  The  holes  were  of  various  sizes, — 
from  the  smallest,  which  was  2]/2  inches  deep  and  3  inches  wide,  to 
the  largest,  which  was  12  inches  deep  and  12  inches  wide,  and  the 
time  occupied  in  digging  them  varied  from  3  to  1 1  minutes.  The 
average  depth  of  those  in  the  King  Street  wall  was  7  1-9  inches, 
the  average  width,  7  1-6  inches,  and  the  average  time  required  to 
drill  them,  6  1-6  minutes.  At  the  Canal  Street  wall  the  average 
depth  was  5  1-5  inches,  the  average  width,  inches,  and  the 

average  time,  5;^  minutes. 

These  facts,  although  interesting,  are  only  of  practical  value  in 


connection  with  a  future  examination  by  the  same  diver  with  the 
same  or  a  similar  instrument.  No  hammer  was  used,  but  the  drill 
was  worked  in  with  one  hand. 

Ninth.  A  characteristic  feature,  which  may  correctly  be  termed  a 
weakness  of  the  King  Street  wall,  is  due  to  the  comparative  inferiority 
of  the  concrete,  in  the  first  or  lower  layer,  deposited  around  and 
upon  the  pile-heads.  The  causes  of  this  inferiority  have  already 
been  mentioned.  Its  results  are  of  a  marked  and  somewhat  import- 
ant character,  for  the  toe  of  the  concrete  base  is  so  badly  broken 
off  and  caved  under,  that  the  front  row  of  piles,  located  directly  under 
it,  give  very  little,  if  any,  support  to  the  wall,  and  should,  for  safety,  be 
disregarded  in  calculating  the  stability  of  the  structure.  The  effect  cf 
this  is  to  place  the  toe  of  the  wall  at  the  second  row  of  piles  two  feet 
back,  and,  therefore,  to  diminish  the  thickness  of  the  wall,  at  the  base, 
two  feet. 

As  the  piles  of  the  second  row,  and  of  all  the  other  rows  in  rear  of  it, 
except  the  one  under  the  heel  of  the  wall,  were  left  extending  above  the 
rubble-stone,  they  doubtless  have  a  good  hold  on  the  better  concrete  of 
the  upper  portion  of  the  lower  layer,  or  of  the  second  layer,  into  which 
many  of  them  reach. 

Another  feature  of  the  King  Street  wall  is  that,  in  many  places,  the 
face  of  the  concrete  base  has  fallen  off  to  a  greater  or  less  depth  through- 
out its  entire  height.  In  some  panels  the  amount  thus  lost  is  trifling  ; 
in  others  it  averages  nearly  a  foot  in  horizontal  thickness ;  while  many 
preserve  their  original  face  almost  intact.  This  loss  of  concrete  does 
not  increase  the  weakness  caused  by  the  breaking  under  of  the  toe  of 
the  wall,  for  the  reason  that  the  part  lost  is  simply  a  portion  of  an  over- 
hang, all  of  which  could,  without  further  impairing  the  stability  of  the 
structure,  be  spared  as  far  back  as  a  vertical  plane  tangent  to  the  outer 
faces  of  the  second  row  of  piles. 

Besides  the  seams  there  are  soft  places,  destitute  of  concrete  stone,  in 
some  parts  of  the  King  Street  base,  but  not  near  as  many  as  were 
detected  at  Canal  Street,  owing,  doubtless,  to  the  circumstance  that  the 
box  used  in  laying  the  former  (2  cubic  yards  in  capacity)  held  twice  as 
much  as  the  one  used  in  laying  the  latter. 

Tenth.  In  filling  the  experimental  caisson  described  in  the  joint 
report,  the  directions  given  were  to  execute  the  work  under  precisely 
the  same  conditions  which  obtained  in  laying  the  concrete  base  of  the 
Canal  Street  section,  which  differed  from  the  method  followed  at  King 
Street  only  in  the  capacity  of  the  box  used. 

The  object  of  that  experiment  was  to  illustrate  the  extent  to  which 
Portland  cement  concrete,  deposited  in  the  manner  and  with  the  appli- 
ances adopted  in  the  construction  of  these  walls,  parted  with  its  sand 
and  the  lighter  portions  of  the  cement.    Besides  the  information  sought, 


05 


and  assuming  that  the  instructions  were  faithfully  executed,  the  experi- 
ment brought  out  the  additional  fact  that  the  concrete  in  these  walls, 
although  rich  enough  in  cement,  was  not  thoroughly  mixed  ;  at  all 
events,  not  as  thoroughly  as  I  have  always  exacted  upon  government 
works,  even  were  the  concrete  was  made  by  hand  ;  while,  in  comparison 
with  mill-made  concrete,  the  degree  of  manipulation  falls  greatly  below 
the  average.  Without  going  into  lengthy  details,  it  will  suffice  to  state 
that  the  cement  was  not  thoroughly  and  uniformly  mixed  with  the  sand, 
and  the  m.rtar  was  not  well  incorporated  with  the  broken  stone.  Those 
familiar  with  this  kind  of  work  will  readily  admit  that  one  additional 
turn  with  the  shovels,  if  properly  done,  may  convert  an  inferior  mixture 
into  a  good  one. 

Eleventh.  In  my  opinion,  the  kind  of  cement  used,  the  manner  of 
mixing  the  concrete,  the  method  and  the  apparatus  employed  in  laying 
it,  and  the  neglect  of  the  workmen  in  allowing  the  laitance  and  river 
filth  to  remain  upon  the  layers,  are  quite  sufficient,  when  considered 
together,  to  account  for  the  condition  in  which  the  works  were  found. 
The  exceptional  inferiority  of  the  lower  course  of  concrete  is  due  to 
exceptional  causes  already  mentioned. 

Twelfth.  Instances  may,  and  perhaps  will  be,  cited,  in  which  appar- 
ently the  same  method  of  construction  in  all  its  details,  has  given  good 
results  elsewhere.  As  a  case  in  point,  it  has  been  reported  to  me,  that 
the  foundation  of  the  light-house,  now  under  construction  on  Race 
Rock,  situated  in  Long  Island  Sound,  some  miles  from  New  London, 
Conn.,  was  laid  in  precisely  this  manner.  Upon  inquiry,  however,  I 
learn  from  the  contractor  that  the  concrete  was  thoroughly  mixed  by 
machinery ;  that  the  box  with  which  it  was  deposited  had  a  close-fitting 
door  on  the  side  so  that  little,  if  any,  wash  came  from  that  direction, 
and  that  in  order  to  diminish  the  wash  on  top,  as  it  had  no  cover,  a  thin 
layer  of  sand  was  spread  over  the  concrete  before  the  box  was 
lowered  into  the  water.  It  may  be  remarked,  also,  that  this  concrete 
was  deposited  in  from  10  to  u  feet  of  water,  within  a  boiler  iron 
caisson,  which  is  left  in  place  as  a  part  of  the  foundation.  The  material 
inside  has  never  therefore  been  examined,  except  on  top  as  the  work 
progressed. 

Some  importance  should  doubtless  be  attached  to  the  fact  that  this 
work  is  located  in  clear  sea  water,  while  the  dock  walls  stand  in  a  mix- 
ture of  sea  water  and  sewage  ;  for  although  Portland  cement,  if  mixed 
up  with  fresh  water,  may  be  deposited  in  sewage  water  without  any 
more  retardation  of  the  set,  except  in  the  washed-out  portions,  and 
without  any  greater  separation  of  the  cement  from  the  sand  than 
would  ensue  in  clear  water,  still  the  parts  that  are  separated  by  the 
sewage  water,  consisting  of  the  lighter  particles  of  cement  and  the 
laitance,  will  never  indurate  at  all. '  In  the  Canal  Street  and  King  Street 


66 


walls  they  constitute  the  seams  and  pockets  already  described.  Simi- 
lar seams  and  pockets  in  the  Race  Rock  foundation  would  in  time 
harden  to  some  extent,  and  therefore  be  less  positively  injurious. 

Thirteenth.  It  appears  that  orders  were  repeatedly  given  to  remove 
the  laitance  and  filth  from  the  surface  of  each  layer  of  concrete  before 
the  succeeding  layer  was  put  down,  but  the  implements  placed  in  the 
hands  of  the  diver  for  that  purpose— a  street  broom  and  a  hoe— were 
not  calculated  to  do  the  work  effectively,  even  if  faithfully  used.  They 
could  only  stir  up  the  filth,  to  be  held  temporarily  in  suspension  in  the 
water,  and  in  the  end  to  become  incorporated,  to  a  greater  or  less 
degree,  with  the  fresh  concrete,  and  produce  pockets  and  seams  of 
washed-out  material,  much  more  injurious  in  character  than  would  have 
been  formed  by  washing  with  the  impure  river  water  alone. 

The  usual  way  to  remove  laitance,  and  the  only  effective  way  that  I 
know  of,  is  to  pump  it  out  through  a  suction  hose,  with  its  lower  end  in 
the  hands  and  under  the  control  of  the  diver  ;  or  the  hose  can  be  man- 
aged from  above,  and  the  services  of  a  diver  dispensed  with. 

Fourteenth.  An  engineer  may  be  willing  to  adopt  a  method  of  doing 
work  which  is  to  be  executed  under  his  constant  personal  supervision, 
or  that  of  assistants  selected  and  controlled  by  him,  which  he  would 
hesitate  to  recommend  to  others  who  might  not  be  similarly  circum- 
stanced. 

Although  I  entertain  no  doubt  whatever  that,  with  proper  care,  good 
masonry  can  be  made  by  depositing  freshly-mixed  concrete  in  water, 
and  even  in  a  mixture  of  sea  water  and  sewage,  still  it  must  be  con- 
ceded that  the  process  is  one  into  which  elements  of  serious  uncer- 
tainty can  easily  insinuate  themselves,  from  a  simple  neglect,  on  the  part 
of  the  workmen,  of  apparently  unimportant  details,  and  should  there- 
fore be  avoided  whenever  it  is  practicable  to  do  so,  and  especially  in 
cases  where  the  engineer  in  charge  cannot  personally  superintend  the 
daily  progress  of  the  work,  or  is  at  all  restricted  in  the  selection  of  his 
agents.  When  I  was  called  into  consultation  with  General  McClellan 
with  respect  to  the  material  and  method  of  construction  to  be  adopted 
for  the  masonry  portion  of  these  bulkhead  or  quay  walls,  I  recommended 
beton  blocks,  laid  as  alternate  headers  and  stretchers,  and  I  have  seen 
no  occasion  to  modify  the  opinions  I  then  held. 

If  I  had  the  wall  to  build,  as  a  government  work,  I  would  probably 
adopt  the  beton-in-mass  method,  in  order  to  lessen  its  cost  ;  using 
Rosendale  cement  concrete  containing  some  common  lime,  and  deposit- 
ing it  with  a  tremie,  upon  a  close  platform  of  planks  resting  on  the  pile- 
heads.  Under  those  portions  of  the  wall,  where  the  layer  of  dock  mud 
was  found  to  be  exceptionally  deep,  I  would  broaden  the  base  of  the 
piling  by  inclining  the  piles  of  the  two  outer  rows  ;  but  generally, 
where  conditions  more  favorable  to  stability  existed,  I  think  the  bed  of 


67 


stone,  placed  around  and  in  front  of  the  pile-head,  could  be  safely 
depended  on  to  resist  all  outward  movement  from  earth  pressure  in  the 
rear.  Respectfully  submitted, 

Q.  A.  GILLMORE,  ' 

Lieut. -Col.  Corps  of  Engineers, 
Bvt.  Major-General  U.  S.  A. 

To  the  Commissioners  of  Docks,  New  York  City, 
February  15,  1876. 


68 


LOG,  AS  KEPT  BY  MR.  WORTHEN,  OF  REPORTS  OF  DIVER 
MR.  JOHN  BURT,  AND  EXAMINATIONS  OF  CON- 
CRETE WALL,  CANAL  STREET  DOCK. 

Panel No.  3.  October  28,  1875.  Shutter  raised  for  examination  of  face. 
Offset  good,  wall  good.  1  foot  down  below  offset,  a  soft  seam ;  ^f-inch 
drill  can  be  forced  in,  in  some  places  1 5  inches,  in  some  only  2  inches  ; 
width  of  seam  1  inch.  4  feet  down  another  seam,  about  the  same  as  first 
seam,  both  extending  across  panel.  8  feet  down  a  third  seam,  from  2 
to  5  inches  wide ;  can  run  drill  in  about  18  inches.  Felt  down  through 
the  mud  ;  face  seems  good  as  far  I  can  feel ;  panel  very  good  except 
seams.  Time  occupied  in  drilling  hole,  with  a  steel  drill  21  inches  long, 
1  inch  thick,  pointed  to  %  inch,  9  minutes  ;  no  sort  of  hole,  2  inches  in 
diameter  by  yz  inch  in  depth  ;  location  of  hole  between  first  and  second 
seam,  about  6  inches  above  second  seam.  Holes  were  invariably  drilled 
by  striking  with  the  drill  itself,  without  any  hammer. 

Panel  Nos.  4,  5  and  6.    Shutters  in. 

Panel  No.  7.  October  27,  1875.  Shutter  off.  Granite  wall  commences. 
This  panel  was  examined  after  panel  8  ;  upper  seam  as  before  (panel  8), 
except  that  it  gets  wet  again ;  second  seam,  same  as  before,  but  not 
quite  as  wide  ;  third  seam,  same  width  all  the  way  across.  Could  shove 
in  drill  1  foot ;  can  put  my  arm  and  drill  2  feet  under  the  foundation  ;  it 
seems  as  if  a  plank  reached  under  south  pile  and  extended  northerly 
about  6  feet ;  f-inch  gas-pipe  driven  into  lower  seam  26  inches ;  got 
it  in,  in  two  places ;  drilled  hole,  y/z  inches  deep  by  4  across,  in  6 
minutes  ;  not  quite  so  hard  as  others. 

Panel  No.  8.  October  27,  1875.  Upper  seam,  about  3  inches  wide, 
without  cement,  runs  across  panel.  Outside  stone  can  be  pulled  out  by 
hand.  Middle  seam  slight,  but  extends  across  ;  drill  cannot  be  shoved 
in.  Lower  seam,  1  foot  wide,  just  the  same  as  before.  Drill  shoved 
in  whole  length,  does  not  seem  to  strike  a  stone.  About  8  feet  down, 
feel  a  little  solid  wall  below.  Face  between  seams  pretty  good,  but 
chipped  in  a  little  in  places.  Offset  good.  Diver  now  took  down  a 
rod  and  marked  position  and  width  of  seams. 

First  seam,  26  inches  down,  5  inches  wide. 

Then  3  feet  space. 

Second  seam,  2  to  4  inches  wide. 

3.3  inches  space. 

Third  seam,  13  inches  wide. 

To  bottom,  2  feet. 
Panel  No.  9.    October  27,  1875.    First  seam  widens  (comparison 


69 


with  10).  Specimen  brought  up  :  a  bluish  deposit,  seemingly  of  cement 
and  sewerage  ;  broke  readily  in  the  fingers,  and,  after  exposure  for 
some  weeks  to  air,  showed  little,  if  any,  signs  of  setting ;  seam  extends 
across  panel.  Second  seam,  about  4  feet  down  ;  extends  across  panel  ; 
no  wider  than  in  10.  Third  seam,  about  8  feet  down.  Specimen  brought 
up  from  north  side  out  of  wall  at  the  seam :  soft,  so  as  to  be  readily 
punched  with  drill ;  seam,  1  foot  wide ;  balance  of  face  of  wall,  except 
seams,  not  bad  ;  depth  of  face  exposed,  about  10  feet.  Diver  went 
down  a  second  time  with  hoe  and  bucket,  and  brought  up  nearly  a 
bucketful  from  third  seam  ;  it  was  of  a  soft  clayey  consistency, 
probably  cement  and  sewer  deposit,  which  was  left  for  some  weeks  in 
the  shanty  office  at  the  dock,  and  showed  no  signs  of  setting. 

Panel  No.  10.  October  27,  1875.  Seam  still  continues,  and  another 
seam  of  same  kind,  about  7^  feet  down  ;  brought  up  a  specimen  of  last ; 
a  weak,  bluish  deposit,  probably  of  cement  and  sewer  deposit.  Could  not 
make  a  hole  in  face  by  striking  with  drill.  Knocked  off  a  few  chips. 
Three  seams  all  the  way  across  panel ;  first,  2  feet ;  second,  4  to  \% 
feet ;  third,  7  feet  down  from  offset.  Face  not  as  good  as  above,  but 
pretty  hard  ;  uncovered  but  little  below  7  feet.  Face  good,  with  the 
exception  of  the  seams. 

Panel  No.  11.  October  27,  1875.  Same  soft  seam  as  in  12,  but  a  little 
higher  up,  about  21  inches  below  offset ;  runs  across  panel  Drilled 
hole  about  4^  feet  below  offset,  \Y2  inches  deep,  in  seven  minutes. 
Found  two  holes  in  face  about  2  inches  diameter.  Could  stick  drill 
in  one  20  inches,  in  the  other,  1  foot. 

Panel  No.  12.  October  27,  1875.  Soft  seam,  about  2  feet  below 
offset.  About  across  panel  could  shove  drill  in  readily  about  1  foot ; 
appears  like  a  seam.  Drilled  hole  about  2  feet  below  offset,  1%  inches 
deep  in  eight  minutes. 

Panel  No.  13.  October  27,  1875.  Central  panel,  beneath  pier, 
exposed  for  only  1 5  inches  below  offset.  Face  and  offset  good.  Drilled 
small  hole,  about  3  inches  deep,  in  five  minutes. 

Panels  Nos.  14  a?id  15.  October  28,  1875.  Could  only  get  to  off- 
set, which  seemed  good. 

Panels  Nos.  16,  17  and  18.    Shutters  in. 

Panel  No.  19.  October  28,  1875.  21  inches  down,  a  seam  %  inch 
wide  across  panel.  4  feet  down  could  feel  another  seam,  but  old  timber 
in  the  way.  Face  between  seams  good  ;  no  place  where  stone  can  be 
pulled  out  of  the  face. 

Panels  Nos.  20,  21,  22  and  23.    Shutters  in. 

Panel  No.  24.  November  3,  1875.  36  to  42  feet  north  of  pier. 
Specimen  brought  up  from  offset,  which  is  broken  all  the  way  across, 
about  1  foot  down  :  a  small  seam  across  panel ;  scantling  in  wall 
embedded  about  3  inches  down.    Extends  within  6  inches  of  south 


70 


end  panel.  Could  push  bar  (^-inch  chisel-pointed  steel  rod)  into 
seam  about  8  inches;  seam,i  to  1%.  inches  wide.  Next  2  feet  below 
seam  :  wall  smooth  and  good.  Next  1  foot  bad,  soft ;  could  stick 
bar  in  18  inches,  in  places  varying  in  width  from  3  inches  to  1  foot; 
could  not  get  down  onaccount  of  dock  logs. 
Panels  Nos.  25  and  26.    Shutters  in. 

Panels  Nos.  27  and  28.  November  3,  1875.  58  to  72  feet  north  of 
new  Pier  34.  Shutters  taken  off  and  posts  between  panels  removed  ;  (72 
feet)  offset  broken  off  and  soft  to  1  foot  down  ;  could  shove  ^-inch  bar 
in  8  inches.  General  face  rough,  with  soft  spaces  in  it,  down  6  feet ;  part 
of  the  shutters  still  in.  No  appearance  of  seams.  (58  feet)  brings  up 
specimen  of  offset  ;  soft  for  about  1  foot  down  ;  2  feet  more,  rough  with 
soft  places.  Next  3  feet  down,  good  face ;  6  feet  only  exposed, 
drilled  hole  4  feet  down,  6%  deep  by  6  inches  diameter,  in  5  minutes ; 
could  pick  out  stone.  Specimen  brought  up  of  a  fair  set,  but  with 
streaks  of  cement  deposit. 


Rear  of  Wall. 

Pa?iel  No.  7.  October  28,  1875.  Top  edge  good,  all  the  way  across  ; 
small  seam  from  12  to  18  inches  down,  very  narrow ;  got  in  y{  rod,  in 
one  place  about  4  feet.  Another  very  narrow  seam,  just  felt  it  with 
the  rod.  Face  of  wall  at  4  feet  down,  very  rough,  not  as  good  below 
as  above  ;  can  get  down  about  7  feet. 

Panel  No.  8.  October  29,  1875.  About  yz  of  wall  good  ;  seam,  1  foot 
down,  from  J^to  3  inches  wide  ;  seam,  4  feet  down,  from  4  to  8  inches 
wide,  at  5^  feet,  face  broken  and  rough  ;  about  7  feet  of  face  exposed  ; 
brought  up  specimens  in  bucket  taken  off  with  a  hoe  ;  stone  with  but 
very  little  cement ;  scraped  in  to  the  depth  of  4  or  5  inches ;  grows 
a  little  harder  as  you  get  in  deeper. 

Panel  No.  9.  October  29,  1875.  From  top  of  wall  down,  1  foot, 
generally  soft  ;  can  put  in  y%  rod  from  4  to  5  inches  ;  next  4  feet  down, 
good.  Then  a  break  from  3  to  8*4  inches  in  depth  to  bottom  of  wall  ; 
broken  out  entirely  across  panel  ;  face  very  rough,  can  pull  out  stone 
easily ;  about  same  specimens  brought  as  from  last  panel  (8)  ;  could 
not  reach  any  piles. 

Panel  No.  10.  October  29,  1875.  The  soft  place  in  preceding  panel 
(9)  extends  into  this  panel  about  2  feet  ;  seam  runs  across  panel  12"  at 
south  end,  and  9"  at  north  end.  Below  top  of  wall  narrow  seam  ;  could 
not  penetrate,  with  Y%  rod,  above  3  inches  ;  face  good  for  $  feet  down  ; 
then  broken  out,  same  as  in  last  panel,  across  the  whole  face,  clean  to 
the  bottom,  from  6  to  8  inches  deep  ;  could  not  get  at  any  of  the  piles. 

Panel  No.  1 1.    October  29,  1875.    Small  upper  seam,  pitches  toward 


71 


the  north  to  12  inches  down ;  very  narrow;  down  to  break  all  good  ; 
below  generally  broken  on  face,  but  not,  in  any  place,  to  more  than  a 
depth  of  5  inches,  clear  across  the  face  of  the  panel ;  drilled  for  six 
minutes  at  a  place  about  3  feet  down,  but  could  not  make  a  hole. 

Panel  No.  12.  October  29,  1875.  Small  seam,  1  foot  down,  narrow  ; 
can  get  y%  rod  in  from  6  to  8  inches  ;  face  very  smooth  for  5  feet  down, 
then  the  break  commences,  as  in  panels  above.  So  many  old  piles 
that  I  could  not  examine  fully  from  break-down,  but,  as  far  as  tried, 
not  more  than  4  inches  deep  at  any  place.  Could  not  get  under  con- 
crete at  bottom  ;  felt  one  pile  out  beyond  face  of  concrete. 

Panel  No.  19.  October  29,  1875.  General  face  pretty  good.  1  foot 
down,  small  }£-\nch  seam  across  panel  ;  forced  in  rod  about  3  inches. 
4  feet  down,  a  large  seam  \yi  inch  wide ;  forced  in  the  y%  rod  from  6 
to  12  inches.  Rip-rap  some  2  feet  below  bottom  of  concrete.  Could 
count  5  piles,  but  could  not  feel  the  head  of  any  of  them  ;  could  feel 
in  between  the  piles.    General  face  appears  to  be  pretty  good. 

From  top  of  stone  to  first  seam,  9  inches  ;  from  first  seam  to  second 
seam,  18  inches  ;  width  of  second  seam,  2  inches  ;  from  second  seam 
to  bottom,  6  feet  7  inches  ;  then  space  of  2  feet  to  broken  stone. 
Specimen  of  soft  deposit  broken  from  top.  Drilled  hole  about  4  feet 
down,  \}/z  inch  deep  by  2  inches  diameter,  in  6  minutes  ;  very  hard. 

Panel  No.  20.  October  29,  1785.  General  face  pretty  good  all  the 
way  down.  About  2  feet  down  there  is  a  seam  in  which  the  y&"  rod 
could  penetrate  about  3  inches  ;  narrow  all  the  way  across.  At  about 
7  feet  down  there  is  another  seam  about  half-way  across  panel,  not 
over  yz  inch  wide  ;  could  force  y%  rod  in  a  little.  Wall  exposed  for 
about  9  feet  deep,  then  corner  rounded  and  gone  in  about  2  feet ;  could 
touch  pile  at  south  end  about  1  foot  under  the  wall.  Mr.  Radenhurst 
thinks  it  was  made  by  diver  closing  up  a  hole.  Work  laid  in  June. 
Drilled  hole,  \y2  feet  down,  6  inches  deep  by  6  inches  diameter,  in  4 
minutes.    Stone  came  out  easily. 

South  end  of  concrete  wall,  westerly  half  .  October  28,  1875.  A  good 
specimen  brought  up.  This  specimen  was  a  large  piece  to  which  a  cord 
was  attached  by  the  diver,  and  was  drawn  up  by  two  men  ;  it  had  been 
detached  from  the  wall,  probably  by  the  pulling  up  of  a  pile,  and  was 
alone  by  itself.  On  breaking  it  up,  the  set  seemed  very  fair.  Examined 
by  General  Gillmore.  No  marks  of  separation  of  sand  from  cement, 
but  looks  more  sandy  than  the  proper  proportion,  but  no  show  of 
cement  by  itself.  Bottom  seems  good  as  far  as  I  could  get  between 
the  piles  ;  upper  edge  somewhat  rough.  Easterly  half  of  wall,  face 
rough  ;  stone  can  be  detached,  but  specimen  before  taken  up  fair  for 
wall.  Same  all  the  way  across  ;  can  find  no  trace  of  seam.  When 
the  face  is  smooth  the  cement  is  good.  Northerly  end  of  wall,  could 
pick  up  loose  stone  on  top  of  slope,  but  pretty  good  beneath ;  could 


72 


not  run  the  y%  rod  into  it ;  found  piles  coming  up  through  the  con- 
crete. 

January  21,  1876.  Made  personal  examination  of  shaft,  which  has 
been  sunk  in  the  interior  of  Canal  street  wall. 

Panel  No.  9.  Could  not  free  shaft  entirely  from  water.  At  the 
surface  of  the  water,  which  was  —  feet  below  top  of  wall,  concrete 
good  ;  no  show  of  seam  ;  could  not  get  X"mcn  steel  probe  in  at  all. 
About  2  feet  above  surface  of  water,  find  thin  seam  ;  got  probe  in  6 
inches  in  one  place,  in  another  2  feet.  This  seam  extends  entirely 
across  north  side  of  shaft.  Just  above  this  seam  can  break  out  con- 
crete a  little  with  the  probe.  Same  seam  traceable  half-way  across 
west  side  of  shaft;  no  trace  on  south  or  east  side.  At  10  feet  down 
from  top  of  wall,  another  seam  on  west,  north  and  east  sides ;  no  trace 
on  south  side.  Probe  cannot  be  forced  in  much  ;  in  one  place  on 
the  east  side  got  it  in  6  inches.  Directly  above  this  seam  can  break 
out  concrete  with  probe.  These  consist  mostly  of  deposits  of  cement 
and  sand,  from  l/z  inch  to  1  inch  thick,  except  in  one  place,  in  north- 
west corner,  of  3  to  4  inches.  The  cement  in  these  seams  is 
washed  and  without  any  signs  of  setting,  and  corresponding  in  char- 
acter with  those  on  the  outside,  which  have  not  set  after  weeks' 
exposure  in  the  air. 


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